(NASA-CR-193386) TELESCOPE. MEDIA (Lockheed 57 p
Missiles
HUMBLE REFERENCE and
SPACE GUIDE
Space
N93-7269q
Co.) Ue...
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(NASA-CR-193386) TELESCOPE. MEDIA (Lockheed 57 p
Missiles
HUMBLE REFERENCE and
SPACE GUIDE
Space
N93-7269q
Co.) Ue_las
Z9/89
Hubble
Space
0[79_93
Telescope
Reference
Published
National
Aeronautics
For:
& Space
Published
-__
Media Guide
Administration
By:
Missi#es& SpaceCompany,#no. Sunnyvale,
California
CONTENTS
Section 1
Page
1.1
1.2
V
1-1
INTRODUCTION Hubble
Space
1.1.1
Support
Systems
1.1.2
Optical
Telescope
1.1.3
The
1.1.4
Solar
1.1.5
Computers
The
Configuration
1-2
Module
1-2
Telescope
Scientific
Hubble
1-4
Assembly
1-4
Instruments
1-7
Arrays
1-7
Space
Telescope
1-7
Program
1-8
1.2.1
Development
1.2.2
Launch-and-Deployment
1.2.3
Verification
Phase
1-9
1.2.4
Operational
Phase
1-10
1.2.5
Maintenance
THE
HUBBLE
2.1
The 2.1.1
2.1.2
2.1.3
2.1.4
SPACE
Support
Phase
1-11
Phase TELESCOPE
Systems
Structural
1-9
Phase
2-1
SYSTEMS
2-2
Module
and
Mechanisms
2-3
Subsystems
2-3
2.1.1.1
Aperture
2.1.1.2
Light
2.1.1.3
Forward
2.1.1.4
Equipment
Section
2-5
2.1.1.5
Aft
and
2-7
2.1.1.6
Mechanisms
Door
2-4
Shield
Shroud
Instrumentation
2-4
Shell
and
Bulkhead
2-7 Communications
2.1.2.1
High-Gain
Antennas
2.1.2.2
Low-Gain
Antennas
Data
Management
2-8
(HGA)
2-8
(LGA)
2-9
Subsystem
2.1.3.1
DF-224
2.1.3.2
Data
Management
2.1.3.3
Data
Interface
2.1.3.4
Engineering/Science
2.1.3.5
Oscillator
Pointing
2-8
Subsystem
Control
2-9
Computer
2-10
Unit
2-10
Unit Tape
2-11
Recorders
2-11 2-11
Subsystem
2.1.4.1
Sensors
2-11
2.1.4.2
PCS
2-13
Computer
iii
PII_6_D_NG
PAGE
BLANK
NOT
FILMED
Section
Page
2.1.5
2.1.4.3
Actuators
2-13
2.1.4.4
PCS
2-14
Electrical
Power Solar
2.1.5.2
Batteries
Thermal
2.1.7
Sating
2.2.1
2.3
2.4
2.5
2.6
Primary
Distribution
Controllers
2-14
Units
2-15
2.2.1.1
Primary
2.2.1.2
Main
2.2.1.3
Reaction
2.2.1.4
Baffles
Plane
2.2.4
OTA
Equipment
2-16
RMGA
2-18
Assembly
2-19
Assembly
2-20
Mirror
2-20
Ring
2-21 Plate
2-22 2-23
Mirror
Guidance
System
and
Mirror
Focal
Assembly
Structure
2-23
Assembly
2-25
Section
2-26
Sensors
2.3.1
FGS
2.3.2
Wavefront
2-26
Composition
and
Function
2-27
Sensor
2-28
Arrays
2-29
2.4.1
Configuration
2.4.2
Solar
2.4.3
Operation
Scientific
2.5.2
and
Current
2-16
Telescope
2.2.3
2.5.1
Charge
Control
PSEA
Secondary
Solar
and
(Contingency)
2.2.2
Fine
2-14
Control
2.1.7.1 Optical
2-14
Arrays
Power
2.1.6
The
Subsystem
2.1.5.1
2.1.5.3
2.2
Operation
2-29
Array
Subsystems
2-29 2-30
Instrument SI C&DH
Control
and
Data
Handling
Unit
Components
2-30 2-31
2.5.1.1
NASA
Computer
2.5.1.2
STINT
Unit
2.5.1.3
Control
2.5.1.4
Power
2.5.1.5
Remote
2.5.1.6
Communications
2-31 2-31
Unit/Science Control
Data
Unit
Module
Units Buses
Operation
Formatter
2-31 2-32 2-32 2-32 2-32
2.5.2.1
System
2.5.2.2
Command
2.5.2.3
Science
Space
Support
Equipment
2.6.1
Flight
Support
Monitoring Processing Data
Processing
2-32 2-32 2-32 2-33
Structure
2-34
iv
Section
Page
THE 3.1
2.6.2
Orbital
Replaceable
Unit
2.6.3
Orbital
Replaceable
Units
2.6.4
Crew
3.1.1
3.2
Physical
3-1
Camera
3-1
Description
3-2
3.1.1.1
Optical
3.1.2.2 3.1.1.3
The Photon Detector FOC Electronics
3.1.3
Faint
3.1.4
Observations
System
Object
3-5
System
3-6 3-6
Camera
3-7
Specifications
3-7
3.1.4.1
Stellar
3.1.4.2
Measuring
3.1.4.3
Globular
3.1.4.4
Examining
Object
3-2
Modes
Evolution
3-7
Distances Clusters
3-8 and
Solar
Galaxies
System
3-9 3-10
Objects
Spectrograph
Physical
3-10
Description
3-11
3.2.1.1
Optical
System
3-11
3.2.1.2
Digicon
Detectors
3-12
3.2.1.3
Electronics,
3.2.2
Operational
3.2.3
Faint
3.2.4
Observations
The
2-35
Object
Observation
Faint
2-35
INSTRUMENTS
3.1.2
3.2.1
3.3
Faint
2-34
Aids
SCIENTIFIC The
Carrier
Power,
Object
3-13
Spectrograph
3.2.4.2
Supernovae
3.2.4.3
The
Evolution
3.2.4.4
The
Composition
High
Comparison
3.3.2
Physical
Specifications
3-13 3-13
Explosive
3.3.1
3-12
Modes
3.2.4.1
Goddard
Communications
Galaxies and
3-14 Distance
3-14
of Stars
3-15
of Interstellar
Matter
3-16
Resolution
Spectrograph
3-16
with
Object
3-16
Faint
Spectrograph
Description
3-16
3.3.2.1
Apertures
3-17
3.3.2.2
Carrousel
3-17
3.3.2.3
Cross-Dispersers
3-18
3.3.2.4
Digicon
3-19
3.3.2.5
GHRS
3.3.3
Operational
3.3.4
Goddard
3.3.5
Observations
Detectors Software
3-20
Modes High
Resolution
3-20 Spectrograph
Specifications
3-21 3-21
Section
Page
3.4
High
3.6
3.3.5.2
Content
3.3.5.3
Star
3.3.5.4
Quasars
Composition
of the
Extragalactic
Optical
3.4.1.2
General
Observations
Detector HSP
High
Photometer
3.4.4
Observations Measuring
3.4.4.2
Search
3.4.4.3
Occultation
3-25
Operation
Specifications
Stellar for
Magnitudes
Pulsars
Camera
3.5.1
Comparison
of WF/PC
3.5.2
Physical
3-28
and
3-30
FOC
3-31
Description
3.5.2.1
Optics
3.5.2.2
Charge-Coupled
3.5.2.3
Processing
Wide
3.5.5
Observations
Detectors
3-33
Modes Camera
3.5.5.2
Planets
3.5.5.3
Martian
3.5.5.4
When
(Fine
Operational
3.6.3
FGS
3.6.4
Astrometric
Specifications
3-33 3-34
Photographing
3.6.2
3-32 3-33
System
3.5.5.1
Fine
3-31
System
Field/Planetary
3.6.1
3-28
3-29
Field/Planetary
3.5.4
3-28
3-28
Observations
Wide
Operational
3-24
3-28
3.4.4.1
Dust
Hole
Systems
Storms
Galaxies
Collide
3-35
Specifications
for Astrometry
and
4.1.2
Predeployment
4.1.3
Contingencies
3-36
3-37
MISSION
DESCRIPTION
4-1 4-2
Deployment
Launch
3-36
3-37
Observations
4.1.1
3-34
3-34
Wheel
TELESCOPE
3-34
3-34
Sensors)
Sensor Modes
Filter
a Black
in Other
Guidance
Guidance
and
Subsystem
3-27
3.4.3
3.5.3
3-22
3-23
Modes
Speed
3-22 3-22
Binaries
Description
Operational
Launch
Medium
3-21
3-23
3.4.1.1
SPACE
Dispersion
Photometer
Physical
Astrometry
and
and
and
Interstellar
Formation
3.4.2
HUBBLE 4.1
Atmospheric
Speed
3.4.1
3.5
3.3.5.1
4-2
Predeployment
4-2
Checkout for
Launch
and
Predeployment
4-3
4.1.3.1
Launch
4-3
4.1.3.2
Predeployment
4-3
vi
Page
Section 4.1.4
4.2
Mission 4.2.1
4.4
4.1.4.2
Deployment
4.1.4.3
Release
4.1.4.4
Deployment
4.1.4.5
Return
4-3
in Space
into
of Appendages
4-4
Orbit
4-5
Contingencies
4-5 4-7
to Earth
4-8
Operations
4-8
Verification
4.2.1.1
Orbital
Verification
4.2.1.2
Scientific
4-8
(OV)
4-10
Verification
4-11
4.2.2.1
Space
Telescope
Science
4.2.2.2
Space
Telescope
Operations
Operational
Control
Orbital
4.2.3.2
Maneuver
4.2.3.3
Communication
Maintenance
4.3.2
Reboosting
4.4.2
HUBBLE
4-16
Characteristics
4-19
Characteristics Characteristics
the
Space
4-24
Telescope
4-24
Observation
4-25
Procedure
4.4.1.1
Acquisition
4.4.1.2
Data
Observation
and
Observation
4-27
Examples
4.4.2.1
Vela
Pulsar
4.4.2.2
Supernova
4-25 4-26
Analysis
4-27
Observation
4-28
TELESCOPE
PROGRAM
MANAGEMENT
5-1 5-1
Responsibilities 5.1.1
4-20
4-22
Scenario
Observations
SPACE
4-14
4-21
4.3.1
Mission
Center
4-16
Characteristics
4.2.3.1
4-12
Institute
Maintenance
4.4.1
5.1
Placement
Operations
4.2.3
"v
4.1.4.1
Mission
4.2.2
4.3
4-3
Deployment
NASA
5-1
Responsibilities
5-1
5.1.1.1
NASA
5.1.1.2
Marshall
Space
Flight
Center
5-1
5.1.1.3
Goddard
Space
Flight
Center
5-1
5.1.1.4
Johnson
5.1.1.5
Kennedy
5.1.1.6
Other
5.1.2
Space
5.1.3
Lockheed
Headquarters
Space Space NASA
Telescope Missiles
Science
Center Center Facilities Institute
& Space
vii
Company
5-1 5-2 5-2 5-2 5-3
Page
Section
5.2
5.1.4
Perkin-Elmer
5.1.5
Scientific
Contractor
5-4
Corporation Instrument
5-4
Contractors
5-5
Contributions
Appendix A
ASTRONOMICAL A.1
Energy
and
A.I.1
Measuring
A. 1.2
Resolving
A.2
Measuring
A.3
Universe
A-1
CONCEPTS
A-1
Wavelength
A-2
Wavelengths
A-2
Wavelengths
Stars
A-2
Expansion
A-3
B
ACRONYMS/ABBREVIATIONS
B-1
C
GLOSSARY
C-1
D
NASA
E
OF
TERMS
SPECIFICATIONS
D.1
Performance/Operating
D.2
Viewing/Scheduling
ORBITAL
REPLACEABLE
FOR
THE
HUBBLE
Requirements
SPACE
TELESCOPE
D-1 D-1
Requirements
D-2
UNITS
E-1
viii
ILLUSTRATIONS
Figure
V"
Page
1-1
Overall
1-2
The
1-3
Space
Telescope
Assembled
1-4
Space
Telescope
Deployment
1-5
HST
Locks
1-6
HST
Network
Collecting
1-7
HST
Berthed
in Shuttle
2-1
Hubble
Space
Telescope
Configuration
2-1
2-2
Hubble
Space
Telescope
Axes
2-2
2-3
Design
Features
of the
Support
2-4
The
2-5
HST
2-6
Aperture
2-7
SSM
Forward
2-8
SSM
Equipment
Section
2-9
SSM
Aft
and
2-10
The
2-11
DMS
2-12
DF-224
2-13
Data
2-14
Location
2-15
FHST
2-16
Reaction
2-17
Electrical
2-18
Nickel-Hydrogen
2-19
Placement
2-20
Sating
2-21
Light
2-22
Fields
of View,
2-23
OTA
Components
2-24
The
2-25
Primary
2-26
Primary Mirror
2-27
The
2-28
Secondary
HST
Configuration
1-2
Scientific
Instruments
1-5 1-9 1-10
Sequence
on Target
Structural
1-11 Data
1-12
Bay
Components
1-12
Systems
of the
Module
SSM
Door
and
Light
2-5
Shield
Shell
Shroud
High-Gain
2-5 Bays
and
Contents
Bulkhead
2-8
Block
2-9
Diagram
Computer
2-10
Management
Unit
of the
PCS
(Aft
Wheel
Shroud
Main
Door
2-13
Open)
2-13
Subsystem
2-15
Battery
2-15 Protection
on
SSM
Telescope
Ring Mirror
2-20
Instruments/Sensors
2-21 2-22
Mirror
Mirror
2-17 2-18
Progression
Main
Primary
2-12
Equipment
of Thermal System
2-10
Configuration
Assembly
Power
2-6 2-7
Antenna
Functional
Path,
2-4 2-4
Assembly
Detail
2-3
2-23
Assembly
Construction
2-23 2-24
and
Reaction
2-24
Plate
2-24
Assembly
ix
Page
Figure 2-29
Mirror
2-30
Focal
2-31
The
2-32a
FGS
2-32b
Optical
2-33
Solar
Array
2-34
Fitting
for
2-35
Solar
Array
2-36
SI C&DH
2-37
Command
2-38
Flow
of Science
2-39
FSS
Superstructure
2-40
Typical
2-41
Four
2-42
Portable
3-1
FOC
3-2
Layout,
3-3
F/96
Optical
3-4
F/48
Optics
3-5
Photon
3-6
The
3-7
Protostar
3-8
"Photographing"
3-9
The
3-10
Quasar
3-11
The
3-12
Optical
3-13
Two
3-14
Comparison
of Four
3-15
A Planetary
Nebula
3-16
GHRS
Structure
3-17
GHRS
Carrousel
3-18
Data
3-19
Cross-Dispersal
3-20
The
GHRS
3-21
Io's
Hot
Torus
3-22
Spectrum
with
3-23
Epsilon
Aurigae
3-24
Stellar
Collisions
Metering Plane OTA
Truss
2-25
Structure
2-25
Structure Equipment
2-26
Section
2-28
Cutaway Path,
2-28
FGS Wing
2-29
Detail
Solar
Array
Wing
Manual
Stowed
2-30
Deployment
Against
2-30
SSM
2-31
Components Flow,
ORU ORU
2-33
SI C&DH Data
in the
HST
2-34 2-35 2-35
Configuration
2-36
Payloads Foot
Major
2-36
Restraint
3-3
Subsystems
FOC
Optical Relay
Relay System
Relay
Nebula,
with
3-6 A Dark
Preplanetary
Gas
Galaxy
3-7
Cloud
3-8
Matter
A Secondary
3-9
Body
Messier
Hypothetically
FOS
3-5
Layout
System
Horsehead
Elliptical
3-4
Layout
System
Detection
3-3
Systems
3-9
87
Centered
In Messier
3-10
87
3-12
Components Path,
Examples
From
3-13
FOS of Exploding Galaxy
Galaxies
3-14
Types
3-15 3-16
and
Optical
3-17
System
3-18
Three
Grating
of Wavelength Digicon
3-19
Settings
3-19
Orders
3-20
Detector
3-23
Ring Absorption (right) Above
3-23
Lines and
Mystery
Quasar
3-24
Companion
Center
(lower
right)
3-25
Figure _V
Page
3-25
Overall
HSP
3-26
3-26
Optical
System
3-27
Filter/Aperture
3-28
Visible
3-29
Rings
3-30
The
3-31
Wide
3-32
WF/PC
3-6
Wide
Field/Planetary
Camera
3-33
Black
Hole
System
3-35
3-34
Two
Colliding
3-35
3-35
Time-Lapsed
4-1
Shuttle
4-2
RMS
4-3
Deployment
4-4
HST
4-5
Crew
4-6
Orbiter
4-7
Erecting
4-8
Crew
Member
4-9
Time
Allocation
4-10
HST
4-11
Space
4-12
A Portion
4-13
HST
4-14
"Continuous-Zone"
4-15
Observing
Venus
4-16
Using
Moon
4-17 4-18
HST Single-Axis Sun-Avoidance
4-19
TDRS-HST
4-20
MM
4-21
Maintenance
4-22
HST
In Position
on
4-23
HST
in Reboost
Position
4-24
Shuttle
4-25
HST
Instrument
4-26
Data
Transmission
4-27
HST
Passes
Configuration
3-26 Tube,
Rotating
Exploded
Configuration
3-29
Pulsar
Around
3-30
Neptune
Overall
WF/PC
3-31
Configuration
Field/Planetary
Camera
Optics
Design
in Binary Galaxies Star
Lifting
Specifications
4-2
Off
4-3
HST
of Solar
Released
and
Orbiter
the
4-4
Arrays
by Control
Rolling
Moves
Away
HST
Out
4-6
of Bay
4-7
Unbolting for
Telescope
4-9
HST
Ground
of the
the
4-7
Array
4-10
Its Orientation
Nominal
4-12
System
GSSS
Star
4-13
Catalog
4-17
Orbit Celestial
as an
4-19
Disk
4-20 4-20 4-20
Zones Decision
Mission
Out
Occulting
Maneuvers Maneuver
Trip
Reboosting
4-17
Viewing
4-18
Contact
Call-Up
4-5 4-6
Panel
SA Mast
Adjusts
3-33
3-36
Birth
Maneuvers
EVA
3-32 3-33
Imaging
Spiral
3-27
4-22
Process
4-23
Timeline
4-23
FSS
the
4-24 4-24
HST
4-26
Apertures Pathway
4-26
of Shadow
4-28
xi
Figure
Page
4-28
WF/PC
Image
5-1
Space
Telescope
5-2
MSFC
Space
Telescope
Organization
5-3
5-3
GSFC
Space
Telescope
Organization
5-3
5-4
JSC
5-5
KSC
5-6
STSci
5-7
LMSC
5-8
Hughes
A-1
Polarized
A-2
HST
A-3
Calculating
A-4
Angular
A-5
The
Space
5-2
Responsibilities
Telescope
Space
4-29
of a Nova
5-4
Organization
Telescope
Organization
5-5
Organization Space
5-5
Telescope
Space
Telescope
5-6
Organization
5-7
Organization
A-1
Light
Wavelength
A-2
Ranges
a Star's
Parallax
A-3
Measurement
Hubble
A-3
Law
A-4
xii
TABLES
Table
Page
1-1
HST,
1-2
Instrument
3-1
Faint
Object
Camera
3-2
Faint
Object
Spectrograph
3-3
GHRS
3-4
Goddard
3-5
High
3-7
Fine
5-1
Instrument
5-2
Space
E-1
HST
Scientific
Instrument
Specifications
Development
Grating
Speed
Teams
Guidance
Sensors
Ranges
and
3-13 Spectral
Spectrograph
Equipment
3-18 3-21 3-28
Specifications Teams
Resolutions
Specifications
Specifications
Development
Telescope
3-7
Specifications
Resolution
Photometer
1-8
Specifications
Spectral
High
1-3
3-36
(IDTs)
Responsibilities
ORUs
5-7 5-8 E-1
×iii
Section
I
INTRODUCTION When
Galileo
scope
peered
nearly
through
400 years
precedented
period
his small
ago, it resulted
tele-
in an un-
of astronomical
discovery.
When NASA_s Hubble Space Telescope (HST) is placed into orbit to begin its observations of the heavens, expected the
it will usher
in a period
to be as astounding
introduction
of the first
Ground-based because
through
the
has
always
observations
earth's
atmosphere,
which
ing starlight
and
must
turbulent, absorbs
particle-filled
severely
limits
thinnest
remnants
astronomers The
Space
will be able brightness
farther
same
brightness
out
in space that
The
25 times
fainter
from earth. astronomers 250 times
than
can
HST than
titude
of stars.
died
over
The
Hubble
partnership
discovered
time
is the product
NASA,
contractors,
distance
Bang" theory (The Hubble
the
and
Appendix
objects
seen
will provide universe
visible,
The
It is named astronomer
and
even
quasi-stellar clarity
Telescope
will view
possibly
fast
a major
it recedes
basis
of the beginning Law is discussed
A" "Astronomical
Space
Telescope
unusual objects
(or fineness
solar
phenomena (quasars),
of detail)
eled
as for
stars, systems,
such
as
with 10 times of earth
of the universe. in more detail in Concepts.")
It will detect
for
billion
(light-years) light
and
of
starlight
is calculated
to move
between
is estimated
the
telescopes.
that
occurred
rent
expansion
Astronomers stars, of
interstellar
the
on
close
quasars,
cond
apart
1Astronomtcal
visible
sky,
(an arcsecond
terms
only
one-tenth
is a slender
and concepts,
arcsewedge
such as "light
of
years",
1-1
other
black unusual
are explained
holes,
of the curBig Bang.
and for
answers
and the future interest will
exploding
A, "Astronomical
of
the effect
galaxies,
phenomena.
m Appendix
years
development
light
questions about the beginning the universe. Of particular
uni-
phenomena
the
of galaxies,
clouds
it takes The
15 to 20 billion
following
study
the composition
has trav-
time
and
first space
distance
in space.
to the beginning
phase can
that since
as the
points
to be
close
as the
repairable
years,
The HST will be able to separate stellar objects that seem indistinguishable because they are so in the
from
for the "Big
is designed
maintainable,
observatory.
making
galaxies,
other
after who
of the universe
old, so the HST will see events comets,
European
the internation-
nature
to how
became
long-term,
verse Space
of a
objects
study.
planets,
by recent will be stu-
periods.
Telescope
the expanding
will
and was the first to realize the true nature of galaxies. He derived Hubble's Law, which relates
of the
the farthest reaches of the universe, perhaps far away as 14 billion light years t, available
The
the A dis-
as Saturn
and
al community of astronomers. Edwin P. Hubble, an American
an object
currently
in
obtained
missions
between
Agency,
us. His work
detect
clarity
longer
Space
an
will
degree, up the sky).
as far away
fly-by
much
a galaxy's
by ground
Planets
satellite
is five
be seen
one
that makes
with the same
NASA
that
the dimmest
than
universe.
to detect
The Space Telescope with an observable larger
will give
to the
Telescope
times
telescopes.
window
a particular
of
Space Teleabove all but
of atmosphere,
an open
object
incom-
of
"pie"
tant galaxy, just a faint dot of light seen from the surface of the earth, will be resolved into a mul-
Space
astronomical
observations. Placing the Hubble scope in a 330-nmi (607-km) orbit, the
been
be made
and distorts
1/3600th
360-degree
be seen as
telescope.
astronomy
hampered
of discovery
and productive
angle,
Concepts."
to of be and
I.I
HUBBLE SPACE CONFIGURATION
The
major elements
TELESCOPE
of the HST are
Assembly (OTA), the (Sis), and a Support
ule (SSM)
structure
mechanical
support
Sis. Figure
that
houses
systems,
and Table
tions for the Hubble scientific instruments.
and
the telescope,
and
the
1-1 gives
Space
the Optical
five Scientific System Modelectronic
1-1 illustrates
configuration,
structures,
tems
Telescope Instruments
the
the
overall
HST
the specifica-
Telescope
and
its
The
overall
array
panels
storage The
Support
Systems
The Support Systems and the five Sis. earth-based
Module
Module encloses the OTA Like the dome of an
observatory,
the
SSM
contains
all
and
the Hubble
spacecraft
weighs 25,500 four antennas
power
Space
is 42.5
subsys-
Telescope.
ft (13 m) long and
ib (11,600 kg). On the outside are for communications, two solar that collect
energy
bays for electronic
SSM consists
for the HST, and
gear.
of the front-end
light
arrays
and
mounted
on
feet
provide
long,
light) in turn, receive
the
to charge
high-gain
forward
the spacecraft
ANTENNA
antennas
shell.
electrical
power the HST. information.
GAIN
The
The
arrays,
energy
(from
batteries antennas
APERTURE
which,
DOOR
SHIELD PRIMARY MIRROR
CONTROL
OPTICAL
SENSORS
(3)_
AFT
SCIENTIFIC INSTRUMENTS AXIAL
(4)
RADIAL SOLAR
Figure
1-1
Overall
1-2
HST
Configuration
ARRAY
(2}
40 sun-
send
MIRROR
GUIDANCE
are
(2)
SECONDARY
FINE
shield,
with an aperture door that opens to admit light. The shield connects to the forward shell. The solar
1.1.1
electronics,
to operate
and
Table
1-1
HST,
Scientific
Instrument
Specifications
HUBBLE SPACE TELESCOPE Weight
25,500 Ib (11,600 kg)
Length
42.5 ff (13 m)
Diameter
14 ft (4.2 m) at widest
OpticaJ System
Ritohey-Chretten design C,assegraJn telescope 189 ft (57.6 m) folded to 21 ft (6.4 m)
OplJcaJLength
94.5 in. (2.4 m) in diameter
Primary Mirror Secondary Mirror Field of View
12.2 in. (0.3 m) in diameter See inslruments/sensom 0.007 arcsec for 24 hr
Pointing Accuracy
5 mv to 29 mv
Magnitude Range Wavelength Range
1100 to 11,000 Angstroms 0.1 arcsec at 6328 Ang
Angular Resolution OrbR Orbit 13me
330 nmi (607 km), inclined 28.5 ° from equator 94 minutes per orbit
Mission FAINT-OBJECT
15 years
CAMERA
WIDE FIELD/PLANETARY
CAMERA
Weight Dimensions
700 Ib (318 kg) 1
Weight Dimensions
595 Ib (270 kg) 2
Principal Inves0gator Cor_actor
FD. Macchetto, Eur. Space Agny ESA (Domier, Matra Corp.)
Principal Invest_ator Contractor
JA. Westphal, CIT Jet Propulsion Laboratory
Op_cal Modes Field of View
f/96 f/46 11.2, 22 arcsec 2
Optical Modes Field of V'mw
f/12.9 0NF), f/30 (P) 160, 66 ercsec 2
Magnitude
5-28 my
Magnitude Range Wavelength Range
9-28 my 1150-11,000 Ang.
Range
Wavelength Range GODDARD
1150-6500 Ang.
HIGH-RESOLUTION
SPECTROGRAPH
FAINT-OBJECT
SPECTROGRAPH
Weight Dimensions
700 Ib (318 kg) 1
Weight Dimensions
680 Ib (309 kg) 1
Principal Invesligator Contractor
J.C. Brandt. NASA/GSFC Ball Aerospace
Principal Investk:3ator ContractoR
R.J. Harms, ARC Martin Marietta
Apertures Resolution
2 arcsec2target, 0.25 arcsec2science 20(X)-100,000
Apertures Resolution
0.1-4.3 arcsec 2 250; 1300
Magnitude Range Wavelength Range
17-11 rnv 1060-3200 Ang.
Wavelengtt_ Range
HIGH-SPEED
WKJht
Magnitude
Range
PHOTOMETER
19-26 mv 11(X)-8(XX)Ang.
FINE GUIDANCE
Dimensions
600 Ib (273 kg) 1
Principal Inves'dgator Contractor
R. Bless, U. of Wisconsin U. of Wisconsin
Apertures Resolution
0.4,1.0,10.0 arcsec 2 Filter-defined
Magnitude Range Wavekmgth Range
< 24my
SENSORS
Weight Dimensions Contractor
485 Ib (220 kg) 3 Perkin-Elmer Corp.
Astrometfic
Stationary & Moving
Modes Precision
Target, Scan 0.002 arcsec 2
Measurement
10 stars in10 min
Speed
1200-7500 Ang.
Field of V'mw
Access: 60 arcmin 2
Magnitude Range
4-18.5 mv
Wavelength Range
4670-7000 Ang.
Detect: 5 arcsec 2
1 Dimension
=
3x3x7 ft (0.gx0.gx22 m)
2 Dimension
=
Camera - 3.3xSx1.7 ft (lxl .3x0.5 m) Radiator - 2.6x7 ft (0.8x22 m)
3 Dimension
=
1.6x3.3x5.4 ft (0.5xlxl.6
m)
1-3
Next
is the
that
equipment
house
power,
section,
computer,
a ring and
of bays
communica-
tion equipment. At the rear, the aft shroud tains the scientific instruments.
con-
The
10 ft
light
shield
and
forward
shell
are
(3.1 m) in diameter; the equipment section aft shroud are 14 ft (4.3 m) in diameter.
gular
boxes
Wide
Field/Planetary
Optical
The Optical mirrors,
Telescope
support
structure.
and
The
WF/PC
and
tions
but
concentrate
objects. quarters,
Assembly
incoming
baffle
is reflected
that
travels
by the
secondary
primary
mirror,
of the primary
fine
called
the mirrors image
1.1.3
focal
1.
plane,
which
sensors
receive
the
design,
focal
length
length,
eter.
that
a
makes
aberrations
sensors
in
plane
optical
axis,
instrument mounted See
structure
can also
aligned
behind
the
and the
three
radially
Figure
consists
of
and a photom-
ence instruments by measuring precisely. Four of the instruments a focal
act as sci-
star locations are housed in with
primary guidance
(perpendicular
the
main
mirror.
One
sensors
are
to the others).
1-2 for the scientific
High-Resolution
instruments.
the
High-Speed
Object Camera Spectrograph (FOS), Spectrograph Photometer
onto
of
one of two sets
mode, mode,
other
photographic
in two modes:
which
of the
of view,
within
sensitive
operates
Planetary
will view
7.2 arc-
sky, and
which
will look
such
at narrow-
as planets
or areas
galaxies.
The CCDs information
record the incoming light, and the is transmitted to earth as electronic
signals
reformed
and
The
FOC
reflects
pathways.
The
or through
into images.
light down
light, after
devices
objects
faint
long
one
passing
of two optical through
that can block
to see background
(FOC), the the Goddard (GHRS),
(HSP)
are
and rectan-
1-4
objects,
exposure
Spectrographs about
source.
filters
out light from images,
enters
The
be built
up over
image
is trans-
total
transmitted
atomic
to earth,
the incoming
wavelengths, the
spectrographs wavelengths lengths.
can
The
data,
separate
its component tion
images
times.
lated into digital then reconstructed.
there The Faint Faint-Object
types
a detector. The detector intensifies the image, then records it much like a television camera.
of instruments
The guidance
different
func-
is
with
Instruments
two spectrographs,
similar
is aft instru-
is a Cassegrain
WF/PC
er fields
bright
first complement
have
on
of extremely
The
Wide-Field
2.
in the
plane.
two cameras,
FOC
quadrant
min 2 sections
12.2 in.
the scientific
to reduce
a
light
a hole
physical
plates.
For The
the
each
equivalent
is reflected
Ritchey-Chretien,
The Scientific
is 3.3 x
The WF/PC splits the light image into using a four-sided pyramid mirror,
focuses
mirror
mirror,
telescope's
hyperbolic
The
m) primary
Here
a smaller
plane down
light.
through
system
of two
focal
the light
guidance the
into
variation, the
to the
means
"folded"
(2.4
mirror
The optical
which
travels
Then
mirror.
and
light.
light
to a secondary
(0.3 m) in diameter.
consists the
stray
(WF/PC)
of four sensors. The sensors are charge-coupled detectors (CCDs) and function as the electronic
and
absorbs
by a 94.5-in.
then
ments
Assembly
trusses,
The
tubular and
Telescope
Camera
5 × 1.7 ft (1 × 1.3 × 0.5 m).
then 1.1.2
3 x 3 x 7 ft (0.9 x 0.9 x 2.2 m); the
revealing
composition
Hubble
light
Space
and
into
informaof the
Telescope's
light two
can detect a broader range of than is possible from earth because
is no atmosphere Scientists
can
composition,
temperature,
lence
of the
stellar
light,
all from
spectral
to absorb
certain
determine
the
pressure,
atmosphere data.
wave-
chemical and turbu-
producing
the
GODDARD
HIGH RESOLUTION
SPECTROGRAPH
BENCH
WIDE RELD/PLANETARY PICK-OFF __
_
CAMERA
MIRROR
DETECTOR
oPT, A.,.s ENTRANCE
ENTRANCE
APE RTURE
MIRRORS
J
PYRAMIDAL MIRROR
C4X_ING
HEAD
FAINT OBJECT CAMERA -- OPTICAL
INCOMING
LIGHT
BENCH
OPTICS
PATHWAY
-_
_LOAD
STRUCTURE
Figure
ASSEMBLY
1-2
ASSEMBLY
The Scientific
1-5
Instruments
(Page 1 of 2)
APERTURE
HIGH SPEED PHOTOMETER - ELECTRONICS BOXES DETECTOR ELECTRONICS
ASSEMBLIES
SYSTEM CONTROLLER POWER CONVERTER AND DISTRIBUTION REMOTE INTERFACE UNITS EXPANDER UNIT SIGNAL DISTRIBUTION
UNIT
SUBSYSTEM
ELECTRONICS
REGISTRATION
CONNECTOR
FITTING 'C'
BASEPLATE PANEL
FT BULKHEAD
FORWARD
INTE RIOR BULKHEADS
BULKHEAD BOX BEAM
l REGIST
_
FFFrlNG
IMAGE DISSECTOR PHOTOMULTIPLIER OPTICAL PREAMPLIFIERS DETECTOR
A' __
LIGHT ENTRANCE
HOLES
TUBES TUBE SUBSYSTEM
HIGH VOLTAGE POWER SUPPLIES OFF-AXIS ELLIPSOIDAL MIRRORS FILTER/APERTURE TUBES
FAINT OBJECT SPECTROGRAPH -- COMMUNICATIONS HIGH VOLTAGE POWER SUPPLY
F'- ANALOG SIGNAL PRCCESSOR -'_
CENTRAL CENTRAL ELECTRONICS
POWER SUPPLY --_
MICROPROCESSOR
FITFINGS-_
\
--_
/
\ \
MOOULE
/
_
r--
POWE R/SIGNAL CONNECTORS
J
-_(_.c--_---_
"_t_z_---'][-'_"_'_"_:_'_
_
/
OPTICAL BENCH LIGHT PATH _
Figure
1-2
ELECTROMECHANICAL MECHANISMS ENTRANCE PORT ENTRANCE APE RTURE POLARIZER FILTER/GRATING WHEEL
The Scientific
1-6
Instruments
(Page 2 of 2)
The FOS can detect detail in very faint objects, such as those at great distances. The GHRS can detect fine detail in the light from somewhat brighter objects. The FOS can detect light ranging from ultraviolet to red spectral bands; the GHRS detects only ultraviolet light. Both spectrographs operate in essentially the same way. The incoming light passes through a small entrance aperture, then passes through filters and diffraction gratings, which work like prisms. The filter or grating used determines what range of wavelength will be examined and in what detail. Then the spectrograph detectors record the strength of each wavelength band and send it back to earth. The fifth scientific instrument is the HSP. It measures the intensity of starlight (brightness), which will help determine astronomical distances. Its principal use will be to measure extremely-rapid variations or pulses in light from celestial objects, such as pulsating stars. The HSP will produce precise brightness readings. Light passes into one of four special signal-multiplying tubes that record the data. The HSP can measure energy fluctuations from objects that pulsate as rapidly as once every 10 microseconds. From HSP data, astronomers expect to learn much about such mysterious objects as pulsars, black holes, and quasars. The three fine guidance sensors are part of the spacecraft's pointing system. Two sensors lock onto a stellar target. The third can measure the brightness and relative position of stars. These measurements, referred to as astrometry, will increase the accuracy of celestial coordinates.
four-foot mast that supports a retractable wing of solar panels 40 ft long and 8.2 ft wide. The arrays rotate so the solar cells face the sun as much as possible. Each wing's solar cells absorb the sun's energy, and the array electronics convert that light energy into electrical energy. This energy goes to the spacecraft's electrical power subsystem for use or storage. Power is delivered by the batteries, which are charged by the solar arrays. When
during each energy. 1.1.5
1-7
the arrays
cannot
shadow collect
Computers
systems and with ground control. The Scientific Instrument Control and Data Handling (SI C&DH) unit controls the Sis, receives and formats science data, and sends it to the communications system for transmission to earth. 1.2
THE HUBBLE PROGRAM
SPACE TELESCOPE
The Hubble Space Telescope project is a multi-phase NASA program aimed at orbiting a large observatory in space for use by the international astronomical community. The program has five distinct phases: •
Development, HST.
•
Launch and deployment of the completed Space Telescope. Verification of the system and scientific functions of the HST.
Solar Arrays
The Space Telescope solar arrays will provide power to the spacecraft. The arrays are mounted on opposite sides of the HST, on the forward shell of the SSM. Each array stands on a
orbit,
into the earth's
There are two computers in the Hubble Space Telescope. The data management subsystem, through the DF-224 computer, handles data and command transmission between the HST
• 1.1.4
the HST moves
assembly,
and testing
•
Operations employing tific instruments to about the universe.
•
Maintenance of the spacecraft ensure and extend its scientific
of the
the HST and its scienproduce information as needed mission.
to
Coordinating
the overall
program
AL.
Marshall
Center,
is working
where
son Space
with
the HST
Center,
at George C. in Huntsville,
during
phase;
the
the
contributing Space
Telescope
conduct team
strument tractors and
the telescope's
as Mission
tractors
who
and
operation
Agency,
vital
components; Institute,
contributed
principal investigators, that created the five
will
Goddard
; and
con-
ments,
Company
many
The
Development
Hubble
subcon-
Telescope
project
over 50 years of inquiry and study bility of an orbiting observatory mers. Led by NASCis Center, astronomers worked
development
and
its scientific
Congress shall
Space
Sciences
and
Lockheed Danbury,
ment.
Hubble
Space
Hughes
built of much
Danbury
sensors
astronomers,
called
Center,
in Greenbelt,
and
and instru-
their
subcontractors
organi-
appear
instruments Office
of
Space
&
Space
Perkin-Elmer
Corporation,
prime
Telescope
Company,
contractors project
for
project
or supervised
Systems,
and
building
the
components,
developers to 1-2
in
subcontract
Inc.,
and the
ref.
Chapter
1-8
5.
separate and
equipment
subcontractors
Lockheed.
Sealed
Instrument Teams Principal Investigator
built
the
in
a sterile
Development
Team Subcontractor
E D. Macchetto European Space Agency
Domier Corporation British Aerospace Mab'a-Espace
Faint Object Spectrograph
R J. Harms, Applied Research Corp.
MartinMarietta Corporation
Goddard High Resolution Spectrograph
J. C. Brandt, Goddard Space Flight Center
Bail Aerospace
High Speed Photometer
R. C. Bless, University of Wisconsin
Space Astronomy Lab. University of Wisconsin
Wide Field/ Planetary Camera
J. A. Westphal, California Institute
JetPropulsion Lab
of Technology
is
sent the
Faint Object Camera
are
develop-
of the equipment
Optical
for
who
After
Instrument
under
contractors and
space
development
of
instruments 5-2.
Table
since
list
Telescope in Table
in 1977. Mar-
and
NASA
to Marshall
Lockheed
guidance
Space shown
equipment
Applications.
CA, and
development
] Now
the
CT, are the joint
responsible
of a large
and
Missiles
Sunnyvale, the
of
the
and sec-
investigators
the team
complete
various
Flight have
instruments
the design
Telescope
auspices
into the possifor astrono-
the program
administered
of the the
authorized
represents
Marshall Space and contractors
on the
telescope
built
to this program.
Phase
Space
and primary
led development teams scientific instruments.
Flight
principal
zations, and Table 1-2. The
1.2.1
Space
test-verified
MD, is responsible for the development in-flight testing of the instruments. The
in-
prime
of international
the
as principal
& Space
Corp.1
is
international
observers;
Missiles
A group
which which
an
including
ondary mirrors, and the fine and other optical subsystems.
Space control
Space
and
Perkin-Elmer
designed
(P-E)
organized
Lockheed
Telescope.
OTA,
operations;
developers
Space
Perkin-Elmer
verification
of astronomers
and
John-
Science
science
completed
assembled
will be launched; will operate
several
then
Space
which
European
the
SSM,
Kennedy
Control during deployment; Goddard Flight Center, which will be the ground center
entire
as the project
management center is the staff Marshall Space Flight Center,
clean room, the entire Space Telescopewas assembled, then tested under launch, liftoff, and spaceconditions.
1.2.2
Launch-and-Deployment
During
the launch-and-deployment
Kennedy
Figure 1-3 shows the assembledSpace Telescope in Lockheed's clean room prior to final pre-shipment testing.
Phase
and
Johnson
responsibility Kennedy
for the Space
will place
cargo
bay of the
launch
activities.
phase,
Space the
Centers Telescope
Space
Space
the
and
in the
run
Space
the
program.
Telescope
Shuttle
When
both
share
all pre-
Shuttle
lifts
off, Johnson Space Center's Mission Control, Houston, TX, will take over control of flight.
Johnson
astronauts
has
trained
to perform
the
in the
Shuttle
extravehicular
activities
designed specifically for the Space Telescope, such as manually turning on the spacecraft's internal power. During the Shuttle JSC Mission Control will work with crew and
the Space
trol Center Center.
Once
in orbit,
deploy the
the
by the
Space
The
manipulator
the HST in space.
STOCC
and
for a depiction 1.2.3
Figure
The
1-3
tests completed,
the Space At
Space
more date.
tests
the
to Kennedy Space
to ready
and NASA
Telescope
the spacecraft
Space
flew
Center.
underwent for its launch
Hubble systems
space.
This phase
Running
Flight developed
Telescope
moves
operational orbital ations,
and and
and
tested,
the
into the program's
phases: scientific in-orbit
launch
and
verification, maintenance.
Hubble
Space
four major deployment, science
oper-
work After the mal
1-9
will use (RMS)
After
a check-
Control,
the
Shuttle will reSee Figure 1-4
its first Orbital
by Marshall tests
Space on the
the spacecraft's
func-
30 days
in
Verification Flight
Cen-
HST
subsys-
systemic
ability
in space. verification,
Center,
through
crew
will undergo
over
is called
internal
tems will ensure
Scientific Once
Telescope
testing
and is controlled
to function
will
Phase
Space
tional
ter.
crew
of the sequence.
Verification
The
Assembled
Lockheed
Telescope
Kennedy,
Telescope
Flight
system
Mission
telescope will be released. The main nearby in case it is needed.
Con-
Space
Shuttle
Telescope.
remote
arm to position
Operations
at Goddard
the
Space
Shuttle
out
Telescope
(STOCC)
operation, the Orbiter
tests
run
by Goddard
Space
will put
all science
instruments
to ascertain
that
instruments
the
and conform to NASP_s specificatioris. verification of all scientific instruments, Hubble
Space
operational
Telescope phase.
will enter
its for-
Figure
1.2.4
Operational
1-4
Space (From
Telescope Deployment Left to Right)
Sequence
The
Phase
Space
(STScl), tific During the
the post-verification
Hubble
Space
operational
Telescope
tem will use the following
phase,
observatory
complex
Tracking and and domestic The
Space
Data Relay satellites
Telescope
The trol
network
ground
prised of the following: -- The STOCC, which
controls
operations through the ations Control Center Goddard
of
(TDRS)
system,
programs
for the
Institute
where
Space
scien-
Telescope
sys-
network:
Satellites
Science MD,
will be planned STOCC
operations. The HST spacecraft The NASA communications
Telescope
in Baltimore,
commission
Payload Oper(POCC) at
of the
The
STOCC
tions. center
primary
has
center
of ground
minute-to-minute
spacecraft
STOCC schedules, ence observations.
when plans,
two
and
required, supports
subordinate
conand
the
all sci-
organiza-
The POCC is the ground-based nerve for the HST. It sends all communication
to the spacecraft and The Science Support between
1-10
is the
It provides
the
POCC
monitors telemetry data. Center (SSC) is the link and
the
Space
Telescope
Science
Institute.
The
SSC
supports
scientific
operations, from quick checks of incoming for accuracy to processing and managing completed
data
The
is the scientific
STScI
is responsible selecting assist the
package.
for all operational
and analyzing
collected
by the
teams
an agenda
objectives. will
send
guide
at the
to the
HST DF-224
the
from
pointing
that
target
position, This
it could
on a dime
subsystem.
system
than
the
diameter
Any
of the
five
away
of the coin.
sensor
then
will
target.
That
information
or sensor
Science
to the
teams
science
ments
at and more
Maintenance
ments
percent
mentation unit.
on
the
SI C&DH during a the data
for distribution
Figure
a second that
slightly theless,
back
up each
equipment
most other
in function. There when equipment
of the
NASA
generation
could
Space
already
is con-
of scientific
replace
the
will be exchanged
instru-
original
group.
in orbit,
not on
ground.
Responsibility Marshall, but nance
for this phase currently Goddard will oversee
lies with mainte-
eventually.
During
a
Shuttle
will
Space
bring
Telescope's
the Shuttle stow HST
1-6).
maintenance
and
of the scientific because
instru-
or identical
part, Figure
mission,
up
the
equipment,
orbit,
and
Space
match
grab
the
the
HST with
RMS arm. After ground commands antennas and solar arrays, the arm
place
the
horseshoe-shaped
on the HST has a backup
For example,
ments
lifetime
will be sent
Phase
of the
the
For example,
sidering
bay. The Ninety
to extend
Telescope.
will 1.2.5
and
will be replaced
1-5.
or a fine
to the
Institute (see
fine
the
then sent to the STOCC transmission. From there
will go to the
on Target
years. Maintenance missions will to replace equipment or instru-
Instruments
data
Locks
after several be scheduled
not waver
collect
HST
prostars,
Figure
1-5
the HST batteries
of light squarely
instruments
specified
instrument
HST
Figure one example,
telescope
See
guidance
computer, scheduled
data
is so precise
and
scientific
catalog
computer
The
hold a beam
600 miles
star
the
/
Space
the guide
point
it
satelof two
using
will lock onto
itself.
that
spacecraft,
and
a target,
points.
The
will
targets
selects
coordinates
sensors
by the
STScI
celestial
STScI
by STScI's
by the
guidance
stable
Telescope.
designated
will maneuver
the
the
data
via the TDRS communication HST will use the coordinates
as reference
and,
It
and for
astronomical
working
targeting
stars,
vided
center.
science
Space
of specific
When
Telescope lites. The
the
Hubble
astronomy
have
operations
observers. Teams of astronomers Institute staff in planning, selecting,
observing,
The
data the
platform
Space
latched
HST
Telescope
down
onto
a
special,
in the Shuttle and
in a carrier,
the are
cargo
replacement depicted
in
1-7.
instru-
they overlap
may be times, nonewill need repair. As
1-11
All support equipment and ments are located on the HST a space-suited
astronaut.
The
scientific instrufor easy access by bays
have
hand
STARLIGHT
TRACKING AND DATA RELAY SATELLITE SYSTEM (TDRSS)
DOMSAT
SPACE SHUTrLE
S
....
TDRSS GROUND STATION
Figure 1--6
HST Network
Collecting
Data
and footholds for the crew, and doors opening onto most equipment and instrument compartments. The crew will make repairs while the HST stands in the cargo bay. Then the Shuttle will release the Space Telescope to orbit again.
The Shuttle also can move the HST to a higher orbit, called reboosting. This may be required due to the atmospheric drag on the HST, which is slight but enough to cause the spacecraft orbit to decay and eventually bring the spacecraft back to earth.
Figure 1-7
HST Berthed
in Shuttle
Bay
Eventually, maintenance missions may be performed on Space Station Freedom using an Orbital Maneuvering Vehicle that brings the HST to the station.
,)
Section THE HUBBLE The
Hubble
and
observes
by the
Telescope
specific
Space
spacecraft
•
Space
three
The Support structure
provides services tion, and control. •
The Optical which collects ing light scientific
•
placed
(SSM), other
plane
instruments,
along
plane
Peripheral
the
all
and
four
maintenance
by the
controlled
by
the
in an
and
one
of
the
circumference
Data
Handling
fine
guidance
craft;
two
sensors solar
and
ground
four
unit
Scientific
2-1 Space
The Space
tory,
point
re-energize
antennas
operation the spacethe
send the
Three HST's
and
Space
receive
Telescope
control.
Hubble
shows
the
configuration
of
the
Telescope.
Telescope
performs
observatory
reflecting
the
Telescope.
precisely
arrays between
Figure
ground
supports
of the Space
communications
(OTA), incom-
housed
equipment
and
batteries;
communica-
use
and
(SI C&DH).
an outer
structure
Control
The
systems
for
SYSTEMS
Instrument
and
focal
spacecraft,
Institute.
such as power,
in the focal instruments.
section
earth
systems:
Module the
TELESCOPE
selected
Telescope Assembly and concentrates the
Five scientific aft
Science
houses
the
targets
interacting
System
that
orbits
celestial
Telescope
has
SPACE
2
with
telescope.
powers,
The
points,
a
SSM,
and
very much
like a
medium-sized like an observa-
communicates
with
MAGNETIC HIGH
GAIN
ANTENNA
SSM S" LL SECONDARY MIRROR
SS
MIRROR FINE
GUIDANCE
& MAIN
CONTROLSENSOR(3) OTA
FOCAL
RING
OPTICAL
EQU
BAF;LE
_ _
NG
_.._,_"_
TRUSS
_
RADIAL
Sl
I
_
.,.,,..,,(_Sz::_y._---_
MAIN
It J
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I
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BAFFLE
I
sOTATEIo QUIPMENT
SSM
AFT
SHROUD
FIXED RATE
HEAD GYRO
STAR
TRACKER
&
ASSEMBLY
Figure
2-1
Hubble
U
_'t
MODOLE(,
__
U"'
J"
STRUC','URE •
-,
_
t_((II\_
__ _ { ..-"_
\
(4)
_{_
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X
TORQUER
_
_ L
X
PLANE
BAFFLE
METER
CENTRAL_
_-_'_"-_
(2)
Space
2-1
Telescope
Configuration
,_
SOLAR
ARRAY
(2)
the telescope Light
assembly
from
the observed
the telescope tific for
and
target
is recorded.
the
then
light
to on-board
either
via the spacecraft
computers
is stored
or sent
communication
to
system,
Space
while
Telescope
The primary telescope,
parallel gain
will make
the earth.
97 minutes.
tain its orbital the
The
Support
position end
to end. array
masts
The
masts
(V3)
(see
HST will point and maneuver rotating around two of the axes.
one
or-
will main-
three
axis, V1, runs through
the solar
antenna
spacecraft
along
MODULE
It also
Module
provides
the
that houses the Optical Teleand the scientific instruments.
contains
the electrical
thermal
control,
for the entire include:
power,
data
man-
and communications
Space
Telescope.
Design
its observations
It will complete
The
SYSTEMS
Systems
external structure scope Assembly
systems features
orbiting
bit every
THE SUPPORT
agement,
for analysis.
The
2.1
through
where goes
processing,
passes
of the scien-
information
earth,
an observation.
into one or more
instruments,
This
to ready
•
axial planes. the center
other
(V2)
•
of
two axes
and
Figure
the high 2-2).
outer
structure
Rotating
reaction
torquers
to orient
SOLAR
ARRAY_
V2
wheels and
•
A ring of equipment-section tain electronic components,
•
Computers and handle
•
Reflective
•
Outer
ies, and
doors,
of
Figure
2-3.
these
The major are the:
and
component
designed
in-orbit
are
subsystems
systems
protection
rails
during
features
Structural and Instrumentation
bays that consuch as batter-
for thermal
use
HST
power
the spacecraft
latches, to
magnetic the
equipment
to operate data surfaces
Some
• •
to provide antennas
communications
shells
and
stabilize
Two solar arrays Communications
astronauts nance
+Vl
of interlocking
• •
The
to new targets by three spacecraft
An
for
mainte-
illustrated
of the
in
SSM
mechanisms subsystem and communications
sub-
system + V2
Vl
V3
Figure
References
2-2
Hubble Axes
to these
pointing
instruments
position in orbit.
the solar
Space
axes
are
Telescope
used
by the
to aim at a target arrays,
or change
HST
in space,
orientation
•
Data
•
Pointing
•
Electrical
•
Thermal
•
Sating
A
team
control
subsystem subsystem
power
subsystem
control
subsystem
(contingency)
of
designed structure. Chapter
2-2
management
and The 5.
contractors
subsystem
and
subcontractors
built the components for the full list of team members is in
bAIN ANTENNA EQL HANDRAILS
DIGITAL INTERFACE
DOOR
LIGHT
SHIELD
REACTION WHEEL
ASSY '_NETIC TORQUERS
COMMUNICATION
SYSTEM
COMPUTER
LOW
SOLAR
ARRAY
GAIN
ANTENNA
UMBILICAL
LATCH
IF
PIN
SUN LIIPMENT
SENSOR(3)
SECTION
3ATTERIES AFT
AND
SH ROUD
CONTROLLER
ACCESS
Figure 2.1.1
Structural
2-3
Design
DOOR
Features
of the Support
and Mechanisms
painted
The outer structure of the SSM is composed of stacked cylinders, with the aperture door on top the aft bulkhead
er are the light SSM equipment bulkhead. &
Figure
2.1.1.1
are made
Company
2-4. Figure
Telescope
on bottom.
Fitting
togeth-
shield, the forward shell, the section, and the aft shroud/
They
Space
by Lockheed
and
are
2-5 shows
Missiles
identified
the Hubble
in Space
Aperture
material,
black
Door.
The
aperture
door, covers
the opening to the telescope's light shield. The door is made from honeycombed aluminum sheets. The outside is covered with
2-3
to absorb
and stray
opens
to a maximum
from
closed
position.
the
the
inside
is
light. of 105 degrees
The
telescope
aper-
ture allows for a 50-degree field tered on the V1 axis. Sun-avoidance
of view censensors on
the
to close
door
provide
before
scope's
optics.
The
the sun is within finishes closing
Space
ter
(STOCC) within
door
This
Telescope
door-closing
damage begins
can
takes
the
the
closing
no
Operations
telewhen
20-degree
for
more
Control
override
mechanism the
warning can
35 degrees of the V1 axis and by the time the sun reaches
of V1.
The
fall
ample
sunlight
20 degrees 60 seconds.
10 ft (3 m) in diameter,
Module
The door
door
assembled.
approximately
Systems
solar-reflecting
Subsystems
and
CHARGE
the
than
Cen-
protective
observations
limit.
An
example
that is
LIGHT APERTURE
MAGNETIC TORQUER
HIGH
SSM
GAIN
(4)
ANTENNA,
FORWARD
SHELL
! SSM
EQUIPMENT
SECTION
SSM
AFT
SHROUD
Figure
2-4
The Structural of the SSM
observing
a bright
or edge,
of the moon
2.1.1.2
Light
object,
Components
using
the
to partially
Shield.
The
dark
block
HST
limb,
the light.
light
shield
blocks out stray light. It connects ture door and to the forward shell.
to the aperOn the outer
skin on opposite
to secure
solar
arrays
sides
and
they are stowed. plates,
large
around The Space The
and
plates
diameter
and
there
magnesium,
with
covered
waveguide, are
foot
with
by a thermal
has ten light baffles,
rails
restraint
on the
HST.
from
painted
to suppress
2-5
stray
aperture
door
2.1.1.3
Forward
central
corrugated-skin blanket.
Figure
and
HST
Assembly
light.
Figure
light
shield.
2-6
shows
the
an internal
It is machined
a stiffened,
bay.
low-gain Hand
operating
10 ft (3 m).
the
cargo
forward
is 13 ft (4 m) long, of
the shield
Shuttle
the
communications
for astronauts
extend
will secure
magnetometers.
the shield,
shield
the
are scuff
that
of the spacecraft.
trunnions
within
I;::_BII
the when
latches
on struts
supports its
antenna
the surface and
three
supports
barrel
the array
shield
the
encircle
The
Near
metal
Telescope
antenna and
high-gain
plates
light
latches
the
30 in. from scuff
are
telescope
Internally flat black
2-4
mirror.
section
Shell. of the
assembly The
solar
The forward structure
main
baffle
arrays
and and and
shell is the houses
the
secondary high-gain
2.1.1.4 bays
APERTURE
Equipment encircling
electronic
DOOR 7
vehicular in-orbit
APERTURE HINGE
SUPPORT,-_
/---APERTURE
I\
INTEGRALLY
INTERNAL BAFFLE
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_
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t
and
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_
pins
the
L--HGA
LATCHES
and
when
SUPPORT
Aperture Door Light Shield
the forward
stowed,
and
are latched
flat against
shell and the light shield.
Four
outer
skin has two grapple
the high-gain
antenna
remote manipulator SSM. The forward used
drives,
fixtures, where
hand
and
The
forward
foot
shell
(3 m) in diameter. num plating, internal outside assembled
holds
(see
cargo
Figure
is 13 ft (4 m) long It is machined reinforcing
stiffened panels. The to assure clearance Thermal
rings for
blankets
Going
position,
aft
control
Bay 9
--
Reaction
wheel
Bay 10
--
Scientific
Instrument and
support
Data
management
Communications
Bay 6
--
Reaction
Bay 7
--
Mechanism
the
contents
shows
the
of each
Handling bay
Bay 4 -- Power trunnion support
--
2-8
assembly
Data
Bay 5
contain:
subsystem
trunnion --
clockwise
the bays
unit equipment bay
wheel
assembly
control
location
unit
of the
bays
and
bay.
/--
next to
system can attach to the shell also has a trunnion,
with external
inside.
scuff plates.
apart shell.
the Orbiter
to lock the HST into the Shuttle
and
to support
mag-
netic torquers are placed 90 degrees around the circumference of the forward The
two bays
Pointing
Figure antennas,
the forward contains 10
--
Bay 2 through Unnumbered
RING
2--6
performing
is a dough-
Bay 8
Bay 1
& SA
LATCH
Figure
and
+ V3 (top)
Unnumbered
_
_-SA
crews
extra-
repair. (SSM-ES)
Control Unit
__
spacecraft.
during
barrel that fits between aft shroud. The section
b] LSAIFS
the
of the
DOOR
from
LATCHES-'-_
by Orbiter
bays for equipment
//--APERTURE
trunnion
STIFFENEDsKIN__HGA _
run
serviced
activities
of storage 90%
DOOR
/HINGE
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to
equipment
equipment
A ring
contains
maintenance
nut-shaped shell and
DOOR
SSM
components
This includes
The
Section.
the
FORWARD
SHELL
REINFORCtNGRINGS
_
/
/
7
_
;_
STOWED
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bay,
2-7).
and
from
STOWEO
10 ft alumi-
rings
and
SOLAR ES/FS INTERFACE RING _'INTEG
are on the the OTA cover
the
exterior.
2-5
SKIN
Figure
2-7
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STIFFEN
ED
PANELS
SSM
Forward
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Each
bay
is shaped
outer
diameter
diameter,
like
(the door)
panels
attached
barrel.
Eight
bays
minum
doors
mounted
9 have
to an
have
thermal
covering
hold
m). The
flat
inner
2.1.1.5
Aft
shroud
houses
ing
the
axial
panel
section. doors
crew
are
ference nate
Bays doors
rails
located
The
plane
The
structure instruments.
used
during
honeycombed
radial
aluminum
The
shroud
gas purge
and system
of the scientific vents
used
3REW
equipment
and instruments
foot the
restraints length
Interior
for
and
lights
containing
contains the
HST
low-gain It is made
aluminum support bulkhead instruments
to expel
the gases
prior
PIN SUPPORT
FLIGHT
SUPPORT
2-9
BEAM SYSTEM
SSM Aft Bulkhead
ft (3.5 m)
con-
Orbiter,
and
in-orbit
2.1.1.6
Mechanisms.
ture are functions.
mechanisms used The mechanisms
•
Latches
•
Hinge
to hold drives
erect
PINS
Shroud
and
the
SSM
•
Gimbals dishes
•
Motors
There
and three
four door.
a
high-gain
contamination to launch.
are light-tight;
There
All i.e.,
2-7
hinges actuator.
latches:
latch
a rotary-drive support
and
door
and
and
antenna
and
latches
and
antennas
four
and
and are driven
arrays
high-gain
the hinges
arrays,
various
solar
aperture
the
arrays
nine the
and
struc-
antennas
move
the
to perform include:
the
and
to power
They
linkage
to open
to
are for
Along
antennas
the arrays
to rotate
antenna atof two-inch
structurally
FSS
circum-
beams.
used to prevent
LAMINATE PANELS
the
the
panels
ANTENNA )MB
Figure
can illumi-
umbilical
and
_AIN
AIDS
STIFFENED
UMBILICALS
VENTS
the scientific
the
IRALLY PANELS
SKIN
the can
The rear bulkhead.
thick
ES/AFT SH ROUD INTERFACE RING
ELECTRICAL
outside of astronauts
and
the
launch/deployment
maintenance. taches to the
SI DOORS
REINFORCING RINGS
The
a stiffened skin, internal panels and rings, and 16 external and internal
between
focal
SI DOORS
contain-
bars for support. It is 11.5 14 ft (4.3 m) in diameter.
nections
OTA
aft
On the so Shuttle
along
bulkhead
the
2-9).
A for-
and
the compartments
aft
in
those
pro-
instruments during maintenance or removal of an instrument. The shroud is made of alumi-
longeron long and
Figure
with
+ V3
6
aft shroud
of the shroud.
num, with reinforcing
to interfere
concentrated
(see
AXIAL
enclose the of the bulk-
Bulkhead.
between
and change Hand
enter
RADIAL
sensors and the Wide Field/ are housed radially near the
equipment shroud are easily.
plane
alu-
wheels.
scientific
point
remove
and
the focal
connecting
can
in place.
Shroud
three fine guidance Planetary Camera
light
aluminum
with equipment. stiffened
OTA
four
no stray wavelengths
bays
honeycombed
for the reaction
the
the
than the inner
ward frame panel and aft bulkhead section. Six mounts on the inside head
with
and 5 ft (1.5 m) long. The and stiffened aluminum
frame
viding
greater
3.6 ft (1 m) to 2.6 ft (0.78
are 4 ft (1.2 m) wide section has machined
and
a trapezoid,
for
one
the
for
release
the
using
by a stepper
antennas, aperture a four-bar
motor
called
actuator.
are
three antenna,
also
hinge and
operate
drives: one using
one
for the a
for
each
door.
The
rotary-drive
Both hinges and latches have hex wrench fittings so an astronautcan manually operate the mechanism to deploy the door, antenna, or array if a motor fails. 2.1.2
Instrumentation
and
antennas from honeycomb aluminum and graphite-epoxy face sheets.Figure 2-10 shows the antenna dish.
Communications
Subsystem
HIGH
GAIN
ANTENNA
The
instrumentation
and
communications
sub-
system between
provides the communications loop the HST and the TDRS satellites,
sending
and
receiving
messages,
and
data
through
the
high and
nas
and
passing
the
information
management refer
subsystem.
High
to the effectiveness
commands,
low gain
anten-
to the
data
TWIN
gain and low gain
of the antenna,
AXiS
J
GIMBALS
I
higher
J
being
more
have
The
effective.
larger
The
signal-collecting
communications
ple-channel systems
sages.
The
and
transmitting
science
and
data
data
and
mes-
can
send
data
on
either
Figure
data
under
Each
or taped
antenna
high-gain
antennas
nications
links
Antennas are
to
(HGA).
the
relay
The
primary
science
two
two
frequencies:
MHz
(plus
low-gain
97-minute are not used.
Each
during
the high-gain
the
low-gain
each
antennas
antennas
antenna
antenna gimbal the
mechanism
antenna
General
is a parabolic
mounted
on
and
100 degrees
Electric
a
ple-channel
designed
electronics and
system.
aft bulkhead
MHz
or
10 MHz).
(LGA).
ground
The
commands
data using
the multi-
They are on the light of the
spacecraft,
set
a
2300
MHz.
The
to
tured
by Lockheed,
direc-
made
2255.5
receive
engineering
stability transmit
apart. Each antenna is a spiral frequency ranges from 2100 to
with
in either
and
HST
antennas
Antennas
access
Anten-
180 degrees cone, with
reflector
mast,
with
is not as
position. the
The
or minus
antennas
and transmit
are
of sight.
Low-Gain
shield
two-axis tion.
When
extended,
high-gain
(dish) rotate
orbit.
maximum
line
affect
over
2.1.2.2
minutes
will not
the
using
position
Accuracy
of a given
to
about
90
Antenna
to a fixed error.
commu-
data
operation,
0.01 arcsec
thus,
the
normal
pointing
and,
single-channel access system. When in sight of TDRS satellites, the antennas can transmit
during
can point
na movement
2287.5
ground
The High-Gain
crucial for communications as for pointing the telescope, where the OTA must point accurately to within
High-Gain
2-10
a one-degree
contingen-
cy conditions.
2.1.2.1
•
or
Single-access
as it is gathered,
engineering
A
(broad-
system
simultaneously.
science
f
multi-
access
engineering
channels
transmits
provides
single-channel
for
antennas
areas.
multiple-access
commands
gain
subsystem
and
cast)
both
high
the
2-8
is placed when
in orbit
the high-gain
low-gain
antennas,
can be used while or retrieved, antennas
manufacthe HST
or in emergencies cannot
be used.
2.1.3
Data
The
Management
data
receives
Subsystem
management
subsystem
communications,
commands from the tions Control Center, systems
and
the
scientific
stores, The
•
DF-224
computer
• •
Data Four
• •
Three engineering/science Two oscillators
except OTA.
and
sends
the
subsystem
located
3.
Scientific
from
4.
System
2.1.3.1
unit
and
sends
sent
to the
HST
signals
subsystem
Computer.
by Rockwell
types
tions
into
functional
solar
arrays
Autonetics,
The
of
cessing
systems
(MU),
units
the power stored
to handle
these
central
two as backup; (IOU),
the
It has
is three
with up to 48,000
input/output
orient
monitor
written
(CPU),
for onboard
antennas.
configuration
units
used
sun,
the
specifically
DF-224
is a gener-
(telemetry),
the
point
com-
The computer must format data calcula-
signals
toward
and
The DF-224
computer
radio
programs functions.
in the
four
the
digital
system,
section,
stored
SI C&DH
as clock
engineering computations. execute stored commands,
recorders
equipment
such
is
DF-224 built
units
Commands
2-11
al-purpose
interface
receives
outputs,
the
as
are:
unit units tape
data
or system
diagram.
signals: 1.
such as commands
Figure
it
information
components
in the
data
This subsystem
Then
Received data, status data
puter,
management data interface
for one
Operathe SSM
instruments.
requested.
are
and
Space Telescope and data from
processes,
They
(DMS)
calibrations,
2.
six memory
words
two
pro-
total;
three
as backup;
and
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six power
converter
overlapping DF-224
units
functions
(PCU) as
a
assigned
with
safeguard.
The
.__l
TOPCOVER
is 1.5 x 1.5 x 1 ft (0.4 x 0.4 x 0.3 m) and
weighs
110 ib (50 kg). It is in bay
equipment
section
(see
Figure
1 of the SSM
.
2-12).
TH COMPRESSION °
.
_
-. :.-..-_ 2.1.3.2
Data
management links with
to selected
powers
HST timing decodes each
Unit.
The
unit (DMU), made the DF-224. It encodes
messages units,
Management
HST
units
the oscillators, source.
The DMU
all incoming
processed
and
all DMS
also receives
along
HEAT SHIELD PARTITION
CARD
(TYP)
I GUIDE i ENCLOSURE
is the central
commands,
command
STANDARD
data
by LMSC, and sends and
PAD)
PC BOARD
then
(DIP-BRAZED
and
passes
to be executed. MATRIX I CONNECTOR-
The
data
management
printed-circuit a backplate
and
unit
is an assembly
boards, interconnected external connectors.
of
through The unit
weighs 83 lb (37.7 kg), measures 26 x 30 x 7 inches, (60 x 70 x 17 cm) and is attached to the door Figure The
of equipment 2-13). DMU
C&DH. come
science
data
Engineering
data,
readings
(temperature,
from
each
of the
can be stoi'ed
bay
1
(see
LtNTERFACE CONNECTOR
(DMU
which
HST
from consist voltages,
subsystems.
in the on-board
the
Figure
SI
2-13
etc.), These
engineering/
science TDRS The
FOR
MU-2,
5
,_ \
pcu FOR
_-- MU-1 _ _---MU-3
\
CPU-3,
IOU-3--_
CPU-1,
IOU-2
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tape recorders is unavailable. data
management
appropriate
telemetry
_,'_
_
.r_
deployment
the
LGAs
are
mat
is for faster
performance
I-OU-2
poepoR\ \ \ l/ LE. oPU3 "1 _
MIB
2.1.3.3
Data
interface
units
between other
the
receive
Computer
2-10
from
DIU other
units
are
section.
a subsystem
The
four
and built
and
data
link
interface
and units
management
required, and pass back to the DMU.
to the DMU. in bays
data
subsystem data
the data
unit is in the OTA
for-
evaluation.
management
Each
equipment
only when
also engineered
perform the operations or status information
the DF-224
when
The
the For
diagnostic
Unit.
unit, data
connects
selects
is used
a command
subsystems.
instructions
interface 2-12
(DIU),
via
required.
immediate
Interface
data
also
and
transmission
1
CONVERTER) COVER
telemetry
format format
provide
HST
unit
NO. DC-DC
Unit
if direct
operational, needs
by LMSC,
Figure
Data Management Configuration
of sen-
example, PCU
POWER SUPPLY
COAXCONNECTOR
BOTTOM
receives
sor status data
section
I
The
OTA data
equipment
section;
3, 7 and
10 of the
As a safeguard,
each
DIU
is
two complete dle the unit's "X...__4
units in one; either functions. Each data
part can haninterface unit
is 15 x 16 x 7 in. (38 x 41 x 18 cm)
and
weighs
35 ib (16 kg). Engineering/Science
The
management
tape
recorders
data
that
used
or science to the
ground
can hold up to one Two recorders are
operations;
the third
operations.
weighing
ment
20 lb (9 kg), are
section
2.1.3.5
bays
Oscillator.
highly-stable the
1, 3, and The
central
HST.
It has
provides
pulse,
kg).
backup are mounted ment section.
The
a
required
by
housing
4 in.
and 9 in. (23 cm) long
3 lb (1.4
the
assembly
and
2.1.4.1
sensing
Pointing
oscillator
and
and
a
in bay 2 of the SSM equip-
The
pointing
tains
Space
aligns
the
locked
Control
The four
coarse
on
control
subsystem
Telescope
positional
subsystem
any
is accurate
main-
stability to and
target.
to within
located send
position
a beam
The 0.01
and
remain pointing
arcsec
and
of light on a dime the
maintains
locating
two
HST
to keep
these
stars.
guide
beam
When
realigning
system
selects
new
moves
telescope's
stars
it in the
require and
the
and
same
straying
different
the Space
position
maneuvering position
specific the
sun sensors, and
used
the mag-
assembly,
the
fine
the
guidance
the
reference Telescope
and
devices,
aft shroud,
safemode
that
electron-
8 of the SSM equipment sun sensors measure the
sun.
when
They
also
position
for
to begin
sensors
calculate the
closing
position
sun-orientation
The
the
HST
the
the
modes
magnetic
sensing
magnetometers,
both
light
shield,
that
units
sending
the data
The
system
and
aperture
HST
during
in contingency
rate
the
pointing
pointing
the
line
connected the HST's
assembly
control
to electronic computer.
relative
consists
send unit
relative
of sight
of the
orien-
magnetic
field.
of
information inside
the spacecraft's
system
of two
end
three
underneath the SSM equipnext to the fixed-head star
units
senses
and position
requests guide
until
to
assembly
front
to the earth's
units and
These
consists
the
to the DF-224
measures
gyro
electronic
system on
are
with respect
rate-sensing ment section
by
relative
target
spacecraft,
are sensing
shield
in bay coarse
Sun
trackers. PCS
light
deployment
determine
The
The
of sensors
the rate gyro
sun sensors
of the
initial
Angeles,
hold
gyro assembly,
contingency system. details on these
to the pointing
ics assembly section. The
tation
it could
electronics
mode
trackers,
on the signals
can hold the telescope to that position with 0.007 arcsec stability. If the HST were in Los in San Francisco, without from the coin's diameter.
safemode
It also
operations. (PCS)
to point
specific
five
2-14).
The five types
system, star
special
Subsystem
spacecraft
Figure
pointing
fixed-head sensors.
door. 2.1.4
(see
the retrieval
Sensors.
includes
the DMS computer, called actuators, to
8.
a cylindrical
cm) in diameter
weighing
in equip-
oscillator
timing
spacecraft
includes
netic
recorders,
stored
the
subsystem
of sensors, of devices,
by the PCS are the coarse
is a backup
The
control
types types
both used in the spacecraft See section 2.1.7 for assemblies.
three
12 x 9 x 7 in. (30 x 23 x 18 cm) in dimension
and
(10
engineering
The recorders of information.
or for contingency
Recorders.
includes
be transmitted
in normal
each
Tape
subsystem
to store
cannot
immediately. billion bits
pointing
different and two move
2.1.3.4 data
The
can
to the
bay rate
10.
to the
orbital
plane
control
the
orientation
of the
Space
The
of motion so the of
Telescope.
stars
it is in the
position.
2-11
A fixed-head
star
detector
locates
that
tracker and
is an electro-optical tracks
a specific
star
SUN
SENSORS
MAGNETOMETER
FINE
GUIDANCE
SENSOR
RATE
I
(3)
GYRO
ASSEMBLY
(3) TORQUERS
(4)
COARSE SUN SENSORS
(2)
REACTION
"_
WHEELS
(4)
COMPUTER
\
"_
EQUIPMENT SECTION
FIXED STAR
HEAD TRACKERS
(3)
SCIENTIFIC INSTRUMENTS
BAY BAY
7 --
MECHANISM
CONTROL
8 ----
+ V3
POINTING
CONTROL
RETRIEVAL POINTING
MODE GYRO ASSY (RMGA) AND SAFEMODE ELECTRONIC
8 BAY
6 --
REACTION
WHEEL
REACTION
WHEEL
NO.
1 FWD
NO.
2 AFT
AND
--
REACTION (RWA)
ASSY
(RWA)
(2) 9
INSTR ASSY
WHEEL
(2)
NO.
3 FWO
NO.
4 AFT
10 --
SI CONTROL AND
DATA
HANDLING --
RGA ELECTRONIC CONTROL (ECU)
_- V2
BAY1
--
DATA
MANAGEMENT
COMPUTER
2 - V3
Figure
2-14
Location
2-12
LOOKING
FORWARD
of the PCS Equipment
UNIT
(PSEA)
within
its field
of view.
The three
trackers
are
position
updates. operations
that
computer
offsets
instrument when vers into its initial
the Space orientation.
momentum with magnetic torque. The DF-224 also smooths HST movement to minimize the
calculate
information
position positioning lock onto
teract
with
rate
gyros,
the
before
and
after
to help the fine guidance guide stars. The trackers in-
fine
guidance
at a command
sensors
from
and
STOCC,
vide a reference for targeting. for detail on the star trackers.
See
the
to pro-
Figure
2-15
effects
commands
translates
wheel
coarse sensors
targeting
DF-224
The
Telescope maneuThe trackers also
ground
The
located below the focal plane structure, on the -V3 axis, next to the rate sensor units. The STOCC uses a star tracker as a calibration
of vibration
2.1.4.3 netic
The
torquers,
which
reaction to move
wheels
maintain
also
to
has
two
assemblies
move
the
types and
of
mag-
spacecraft
the
into
and
to move
are oriented
with
only three
assemblies
the
wheels,
section.
transfer
The
HST
wheel
can operate
if required.
in diameter
flywheel
it to
two each
equipment
23 in. (59 cm)
a large
the
The
in a stable
spacecraft.
so that
spin
into position.
braking
are paired,
SSM
use
spacecraft
by rotating
rpm
axes
assemblies
the HST
They work 3000
momentum
of the
optics.
PCS
wheel
momentum
up
wheel
positions.
four
position.
reaction
on telescope
wheel
reaction
the spacecraft.
the
reaction
commanded
The
maneuver
Actuators.
actuators,
into
The
wheel
in bays 6 and 9 Each
and
wheel
weighs
is
about
100 lb (45 kg). See Figure 2-16 for the configuration of the reaction wheel assemblies.
Figure
2-15
FHST Door
three
fine
guidance
The more
detail
later,
of a star. pointing
make
adjustments,
the
guidance
pointing, tional
while
Chapter
the the
angular
accurate sensors
the
third of
This
discussed
most
function
is
Two
Figure2-16
for posi-
stars,
called
PCS
data
Computer.
uses
management
the
The
DF-224 subsystem
Reaction
discussed
in
The
magnetic
the
reaction-wheel
against reaction
_L J_
LI_ :
Wheel
Assembly
pointing computer to
control in the calculate
2-13
tum.
torquers
create speed.
torque
The
to change
torquers
react
the earth's magnetic field. The torque occurs in the direction that reduces the
reaction-wheel subsystem
El ..£2 _'_
a frac-
3.
2.1.4.2
1 ..£2
guide-star
is available specific
El J2
_.f
fine
the target.
perform
in
position
delicate
to within
to pinpoint
measurement
astrometry.
(Aft Shroud
sensors,
measure
They
tion of an arcsecond, of
Detail Open)
The
perpendicular lines.
speed
torquers to
by balancing
provide the
torque
earth's
the momenin directions magnetic
field
The torquers also act as a backup the HST stabilizes its initial orbital during
a system
externally
on
8.3 ft (2.5 ence,
failure.
the
m)
and
Each
forward
long,
weighs
system, when attitude, and
torquer,
shell
except
bays
SSM,
is
around
Before the
in circumfer-
HST. PCS Operation.
pointing
control
To point
subsystem
precisely,
combines
tions of the gyros, reaction wheels star trackers, and fine guidance fine guidance
sensors
provide
from which the Space sitioning.
The STOCC
wheels
to spin,
motion
fine
If needed,
load
the
the
As the HST nears
spacecraft area
has
about
sensors
of the
guide
stars
60 arcmin
take
over
the gyros and cise pointing, HST
the
region
2, the
pointing
0.01
arcsec
which
stand
of the
the
a target guidance with
target.
The
pointing control system can maintain this position, wavering no mgre than 0.007 arcsec, for up to 24 hours
to guarantee
tion exposure hours.
2.1.5
instruments subsystem. solar
array
2.1.5.1
totaling
observa-
10
power
Power
cumulative
The wings
Subsystem
for the
comes
HST
from
major and
the
and
components their
the
electrical are
electronics,
into orbit,
the on-board power
arrays
HST
to deploy
are
and power
from
Solar
discussed
this
the
extended
and
distribution
subsystem
Arrays.
more
the
The
thoroughly
major
wing
source
later
units.
(see
Figure
array
panels,
the HST
Each array wing has assembly. This consists unit,
in this chapter, power.
cell blanket
The electricity
charges
electronics
solar
of electrical
has a solar
energy.
cells
the
drive
to assimilate by the
batteries.
an electronics control of a solar array drive
which
motors
Each
produced
transmits
commands to the wing assembly, ment control electronics unit, extending
positioning and a deploywhich controls
and
retracting
the
wings. 2.1.5.2
Batteries
trollers.
The
and
Charge
six nickel-hydrogen
Current
Con-
batteries
pro-
vide backup power when the HST is within the earth shadow and the solar arrays are eclipsed. When
fully powered,
a maximum power
Electrical
Electrical
a faint-object
time
enough solar
control
power
can un-
reaction wheels to adjust the prethe guidance sensors point the
to within
their
the sun's
Working
is placed
later
The array electronics, the SSM, the OTA, the SI C&DH, and all scientific instruments receive
array
track-
fine
and
the
the power
maneu-
the star
within
duties.
section.
Telescope
Shuttle, provide
updates
sky. Once
two
in the
begin converting solar radiation into electricity. This is stored in the batteries and distributed by
solar
stars,
located
as
speed.
guide
are
the equipment
Then
are
torquers
area,
arrays
2-17).
reaction
spacecraft
the target
in that
attitude
magnetic
preselected
out brightly
the
or decelerating
and
reaction-wheel
ers locate
point
can begin repo-
short-term
pointing
vers.
ac-
the HST toward a new target. sense the HST's vehicular
and provide
to assist
the
and torquers, sensors. The
commands
accelerating
required to rotate The rate gyros
the
a reference
Telescope
solar
the Space
Space
batteries,
100 lb (45 kg).
2.1.4.4
the
located
of the
3 in. (8 cm)
All
each
battery
of 68 amp-hours.
to supply
can produce
This
is enough
the HST
and
its major
3.5 hours
after
switching
for greater
than
tery power
before
as a power
source.
the solar
arrays
systems
must
to batbe used
scientific power
The solar
the two
processed
six bat-
one
teries, six charge current controllers, one power control unit, and four power distribution units.
2-14
arrays
recharge
through
per battery.
the batteries.
a charge Each
charge
current current
also provides
a voltage-temperature
the
battery.
charging
Power
is
controller, controller control
for
......
=A
PWR
PWR
PWR SA ELECTRONICS
sA
CONTROL ASSEMBLY
MECHANISMS]
CMDS
PWR CTRL UNIT
CMDS
P
SSM SA Sis OTA
PWR=i
1
SI
TLM --D,,-ORBITER PWR (PRE-DEPLOYM ENT)
Figure The
batteries
teries
and
minum
are
casing.
doors
520 lb (236
consist The
batteries
of three
2.1.5.3
Power
Units.
The
and
switches
solar
arrays,
trollers.
The
main
power
units.
The
section
(see
Figure
Control
power
control
batteries, power
an alu-
are attached
to the
bays
2 and
unit
interconnects between
and charge
current
control
3, in
Distribution
unit provides
line to the four power power
unit
the conthe
distribution weighs
about
120 lb (55 kg), measures
43 x 12 x 8 in. (109 x 30
x 20 cm), and is located ment section.
in bay 4 of the equip-
The
four
the inside er lines,
power
distribution
of the door switches,
units,
to bay 4, contain
fuses,
Subsystem
2-18).
flowing
control
Power
bat-
inside
and
electricity
Electrical
kg) for three
of 23 cell plates
of equipment
groups
2-17
and monitoring
located
L
on
the powdevices
2-15
Figure
2-18
Nickel-Hydrogen
Battery
C&DH
leading
to the
dedicated and
rest
SI C&DH;
bution 12.5
OTA,
x 45 cm) and Thermal
overall
Each
25 lb (11
plan
controls, covering
15 layers
electric The insulation
of aluminized
ing exteriors. the
cold
passive
tape
with
These
of space
and
builds
reflect
include
paints
protect
and
solar
•
Radiation and MI,I
venting
•
Over
200
where
or
to monitor heater
2-19
temperatures nents
within
mounted
and structures The
each
limits
interfacing
even
ronmental earth
set
subsystem
on the SSM
subsystem
peratures
control
orbit,
equipment
will maintain
and heat
section and Sis.
component
for "worstcase" to "hot"
compo-
with the OTA
fluctuations,
shadow
maintains
for the
events
passage solar
tem-
from from
2.1.7
Sating
guard
(AL)
aperture-door
less,
Specific
patterns
of FOSR
and
the
bulkheads
to
maintain
and
pro-
indicating
the
System
a contingent,
pointing well
redundant
and
on
It
and
called
assembly.
the spacecraft
the
Telescope's
The
sating
occurred the
HST,
to cut
is
atti-
to get maximum
sun
power
by
system
can
with no communications
link to ground control for up to 72 hours. that time, it is assumed, the STOCC the
as
system
electrical
drains.
for
of
the pointing This
the Space arrays
conserve
power
exists
many
components,
hardware
the solar
to safeNonethe-
system uses
and data-management
move
includes
in orbit.
3' or sating
as dedicated
exposure,
SSM
design equipment
operations.
during
analyze
any
Within would
problem
off communications,
that
and
cor-
problem.
the
sun
MLI blankets
thermal
inter-
of thermal
any breakdown
to maintain
of
tape
facing
location
Telescope
tude,
on the exteriors of the equipment section bay doors, with internal MLI blankets on the between
and
emergency
rect FOSR
and
used.
designed
for the light shield
surface
the
Space
against
recontact
Aluminum
placed
components
(Contingency)
Hubble
operate
MLI thermal blankets forward shell
sensors externally
individual
"cold"
equipment
features
scientific
on the SSM, with symbols of protection
minimizing
thermal-protection
the
operations
electronics
operation.
Specific include:
protect
SSM,
safemode
like envi-
exposure
generated
to
shows
type
The
thermal
on the aft shroud
temperature
control
sec-
heat
up.
SSM
dissipating
inside the aft shroud doors, on the aft bulkhead and
the
overlapping The
heat-
FOSR tape exteriors
shields blankets
nally,
Figure
require-
Other
reflective
areas
placing
shroud interiors instruments
tection
against
heat.
using
as
and use of
temperature
on the side of the equipment in orbit shadow
Silverized (AG) and aft bulkhead
an
of the remain-
coverings
techniques
absorptive
most
such
throughout
Optior sil-
of equipment
match
•
blankets
Kapton,
covers
to
to
equipment tion most
en-
heaters,
placement
space
ments,
kg).
uses passive,
Efficient bay
distri-
outer layer of aluminized Teflon Flexible cal Solar Reflector (FOSR). Aluminized FOSR
•
such as multi-layer 80% of the HST exte-
temperatures.
verized
are
10 x 5 x 18 in. (25 x
supplemental
maintain have
weighs
units
instruments,
the SSM.
about
HST thermal
and
Two
Control
ergy-conserving insulation (MLI) rior,
HST.
scientific
two supply
unit measures
2.1.6
The
of the
to the
balance
bays
The sating system automatically monitors the HST on-board functions in Monitor Mode, which the STOCC can turn on and off or override.
The
indicate tioning.
2-16
system all Space If
the
sends
"keep-alive"
Telescope sating
signals
systems
system
alerts
are
that func-
ground
_--
AL FOSR
z- _PS"g °"_
_SM, /
_LHAECM_LAZE__/'_.,.|
I,,L_os_l ,_o_
l;°s;
+VI--F---=_-_
I I
....
__
BLACK--'7,_
VF°S_
_--
IJ
lli-- I
-=},___
_1
_JIII
I
))
._
I
II
//
\\
!..r_ _,j j,,,lllj,,, .._ML'_.... u1_.J'-'II _
ML, #
M_,_
] L
Figure 2-19 control
to a problem,
special
failure
the problem control.
The
Placement
the STOCC
investigation while
the
investigation
sating
team
as a data
or flight
produced
inconsistencies
will classify
expected
performance,
as a flight
The
data
how
If possible,
the
to correct STOCC
be classified investigation
Telescope from the lem. If the situation STOCC may nance mission.
the problem. will
adjust
the
an
unplanned
the
Space
the
progression
of
sating contingency
depending
upon
Telescope.
If a malfunction
threaten initially
the
system
Sun Point
arrays
point
solar
power.
the situation
HST's
will move
into
operating aboard occurs
survival,
follow
the
Software
a
modes the Space
and does sating Inertial
system
will
not
system
operating
90o ML,
complete
2-17
pointing the HST
the
power
control subsyswill enter Soft-
Mode.
the
The
telescope
sating
and
solar
constant
will remain
anticipating The STOCC
sys-
so the
the sun to generate
temperatures
above
within survival
a return to normal must intercede to
the malfunction before any science operor normal functions can be resumed. the sating
through
computer
worsen,
the system
system
under
Problems
that
of the
will be operating
software. will turn
safemode
(PSEA), any
electrical
HST equipment
temperatures, operations.
conditions
control
electronics
Hardware could
If over
assembly
Sun
provoke
to the
Point
Mode.
this action
include
following:
•
A computer
•
Batteries
Hold
Mode. The system will hold the HST in the last position commanded. If a maneuver is in
a marginal
Vehicle
toward
To this point,
mainte-
will
detects
will maneuver
pointing Meanwhile,
sating
problem, or an internal tem safety check fails,
repair ations
ground to solve the probcontinues or worsens, the
consider
___
on SSM
progress,
tem
team then will indicate the probable cause, list the subsystems and components involved, and recommend
Protection
ware
Ira flight system deviated from
failure
-M_.,
If the system
this would
this would
problem.
maintains
If spacecraft
Jh,._ M,,'_=_:_
maneuver, then hold the HST in that position. It will suspend all science operations until the malfunction is corrected.
the problem
or errors,
be classified as a data problem. such as an electrical unit
in a
to evaluate
system
problem.
of Thermal
will call
team
I""_' .;
FOSnJ
malfunction losing
more
than
50%
of
their
charge •
T¢¢o of the three
•
The
data
rate
management
gyro
assemblies
subsystem
failing failing
If these stop
conditions
sending
Sun Point
will
equipment components computer
the
solar coarse
arrays sun
reversed
quickly,
tion
is a
from
lengthy
the
and
com-
turn
if not
will turn
equipment
process
from
Space
Telescope
tion for over
can
72 hours
NORMAL
[
I I I I I I__
HST the
listed
above,
Gravity
the HST
the
PSEA
spacecraft
Gradient
computer
Shuttle
uses
This
by
to earth
orbit-
can retrieve
the
to maneuver
only
in Figure
enters
Mode.
in a gravitationally-stable
until the Space
brought
retrieval
mode
into a survival
magnetic
for major
repair.
2-20 for a diagram
orbit,
torquers. whether and
maintain
The
the misthe HST
See the chart
of the sating
system
any contact
2.1.7.1
PSEA
mode
electronics
and
RMGA.
The
assembly
pointing
safe-
consists
of
of
from
internal
assembly
failure.
It weighs
86
OPERATIONS
!
_cOFTWARE
HARDWARE%
Ii
GYRO
I
ONTROL
•
INITIATE SAFING
•
INITIATE
SI PAYLOAD SEQUENCE ST LOAD
SHEDDING
i •
REASONABLENESS CHECK
ORIENT
SEQUENCE SA TO +
V3 AXIS
I 1
J
STOCC COMMAND
CAUSES
LOSS OF KEEP ALIVES • BATTERY DCHG. >50%
FAIL
• TWO
• SPC LIST EXHAUSTED
GYROS
FAIL
CHECK
•
NO COMMANDS
•
MEMORY TESTS FAIL (PARITY ERROR INTERRUPT AND WRITE
•
FOR
PROTECT
CPU AND FAIL
100 HOURS
I
HARDWARE SUN POINT
I t
+ V3 AXIS TO THE SUN)
r SUN
CHECKS
(ENABLE/DISABLE BY STOCC)
STOCC COMMAND
GRADIENT GRAVITY
INERTIAL HOLD •
MAGNETIC
TORQUER
DUTY CYCLE CHECK EXCEEDED
SOFTWARE SUN
• WHEELSPEED EXCEEDED •
BATTERY DISCHARGE >50%
ANGLE
TO SOLAR ARRAY PERPENDICULARITY CHECK EXCEEDED
VIOLATION)
TIMING
POINT (+ V3 AXIS ORIENT SA TO + V3 AXIS
Figure
TO THE
SUN)
_]
2-20
Sating
2-18
40
electronic printed-board circuits with redundant electronics to run the HST even in the case
this condi-
FOLLOWING
• TESTS
it.
progression.
STOCC
"1 MONITOR
if more continue
this situa-
involving
without
time, cannot
STOCC again must evaluate sion should be discontinued
analysis. The
a reasonable
adjusted
begins
are
beyond
gyro assembly
the
repair
fail, or if the PSEA
The
not required
Recovery
and
systems
al attitude
by the is not
assembly
if contact
delayed
keeps
already
to face
But
Contingency
unit. A payload
and,
STOCC.
operations
off
contin-
the sun, guided If the situation
survival.
will
conserve power. could include the
the safemode
power
PSEA
if the emergency
Telescope
toward sensors.
for the HST's
HST
will begin,
Space
removing
the
the SI C&DH
sequence
done,
to
and,
ues for two hours, sating
the
system
signals.
Mode
command
selected Shut-down DF-224
the sating
the "keep-alive"
In Hardware puter
occur,
System
Progression
INITIATE SEQUENCE FOR RESCUE j
BY STS
ib
(39 kg) and is installed in equipment section bay 8. The retrieval mode gyro assembly, also in bay 8, consists of three gyroscopes that are less precise than the rate gyros. 2.2
THE OPTICAL ASSEMBLY
TELESCOPE
The Optical Telescope Assembly (OTA) was designed and built by the Perkin-Elmer Corporation. Modest in size by ground- based observatory standards, and of a straightforward optical design, the accuracy with which the telescope assembly has been built, coupled with its place above the earth's atmosphere, render its performance superior. As is common practice in the design of large telescopes, the OTA uses a "folded" design, which enables a long focal length of 189 ft (57.6 m) to be packaged into a small telescope length of 21 ft (6.4 m). (Several smaller mirrors in the scientific instruments also use this design to lengthen the light path within the particular scientific instrument.) This form of telescope is called a Cassegrain, and its compactness is an essential ingredient of an observatory designed to fit inside the Space Shuttle payload bay. Conventional in optical design, the OTA is unconventional in every other respect. Large telescopes at ground-based sites are limited in their performance by the resolution attainable by operating under the earth's atmosphere. But the Space Telescope will orbit high above the atmosphere and provide an unobstructed view of the universe. This is why the OTA was designed and built with exacting tolerances to provide near-perfect image quality over the broadest possible region of the spectrum.
The OTA is a variant of the Cassegrain, known as a Ritchey Chretien, in which both the mirrors are hyperboloidal 1 in shape. This form is completely corrected for coma 2 and spherical aberrations to provide what is known as an aplanatic 3 system. The only residual aberrations are field curvature and astigmatism. Both of these are zero exactly in the center of the field and increase toward the edge of the field. These aberrations are easily corrected within the instrument optics. For example, in the Faint Object Camera there is a small telescope designed to remove the image astigmatism. Figure 2-21 shows the path of a light ray from a distant star as it travels through the telescope to the focus. Light travels down the tube, past baffles which attenuate reflected light from unwanted bright sources, to the 94.5-in. (2.4 m) primary mirror. Reflecting off the front surface of the concave mirror, the light bounces back up the tube to the 12-in. (0.3 m) diameter convex secondary mirror. The light is now reflected and converged through the 23.5-in. (60 cm) hole in the primary mirror, to the telescope focus, 3.3 ft (1.5 m) behind the primary mirror. The focal plane is shared between five scientific instruments and three fine guidance sensors by a system of mirrors. In the very center of the field of view is a small "folding" mirror which directs light into the Wide Field/Planetary Camera. The remaining "science" field is divided between four axial scientific instruments, each receiving a quadrant of the circular field of view. Around the outside portion of the "science" field, the "guidance" field is divided among the three fine guidance sensors by their own "folding" mirrors. Each FGS receives 60 square arcmin of field in a 90-degree sector. See
1 "Hyperboloidal" refers mathematically to the shape of the mirror. A hyperboloidal slightly deeper curvature than a parabolic mirror. 2 "Coma"
are aberrations in the image that give it a "tail".
3 Corrected everywhere
in the field of view.
2-19
mirror has a
Figure view.
The
2-22
for the
fields
Optical
Telescope
Assembly
instruments
in that
is a "host"
and fine guidance
it maintains
the
structural
ponents
of
assembly,
the
OTA
the
plane
secondary
and
the
the mirror
Systems
The
assembly
by
Perkin-Elmer;
section
(see
•
The
•
Main
• •
Reaction plate and actuators Main and central baffles
mirror the
the
OTA
systems
are
LMSC
Figure
2-23).
These
primary
assembly
also
parts
2.2.1.1 blank
Primary
Mirror
Assembly
mirror
mirror which
itself is the
scope,
and
assembly
supported structural the
main
provides
rest of the spacecraft, attachment
assembly
chosen
cient,
brackets
up of the
inside the main backbone of the and
central
through linking
baffles. coupling
ring, teleThis
of Corning its very
assures
to temperature facesheets
of glass
are
mirror
The
ring to the
SECONDARY
mirror
ground
coeffi-
The
in which
mirror
two light-
by a core,
or
ribs in a rectangular
weighing
blank,
to shape
MIRROR
8000
results of a sol-
lb.
8 ft. (2.4 m) in diameter, by Perkin-Elmer
/
2-20
Path, Main
Telescope
was
in P-E's
(3) --3 AXIAL
SCIENTIFIC
I
L_
Light
(P-E),
INSTRUMENT
MIRROR
MODULE
2-21
It
minimum
This construction mirror instead
[
Figure
that
glass.
expansion
telescope
separated
PRIMARY
DOOR
Works
changes.
honeycomb
mirror
(ULE)
construction
FINE GUIDANCE SENSOR
APERTURE
primary Glass
low
the
grid (see Figure 2-25). in an 1800-1b (818-kg) id-glass
The
2-24.
to the
a set of kinematic the main
Mirror.
for
which
filling,
in Figure
as ultra-low-expansion
is a "sandwich"
is made
the structural
pictured
is a product
weight primary
are
Primary
is known was
mirror
ring structure
sensitivity 2.2.1 The
Module.
to
these com-
assembly, and
All
built
equipment
for The
primary
assembly,
section.
designed
are
structure
equipment built
Support
sen-
support
and optical-image stability required instruments to fulfill their functions.
focal
of
provides support to the primary mirror and the OTA baffles. It has the following major parts:
the scientific sors
instrument/sensor
(4)
I
(IMAGE RADIAL SCIENTIFIC INSTRUMENT
FORMED
HERE)
+ V3
HIGH
AXIS
GUIDANCE
SENSORS
(3)
RESOLUTION FGS #2
SPECTROGRAPH
"_
SPEED PHOTOMETER OPTICAL
CONTROL
SENSORS
(3)
+V2 AXIS
CAMERA
FAINT
OBJECT
SPECTROGRAPH 2 DETECTORS, SEPARATE APERTURES WIDE
FIELD/PLANETARY INCOMING
(VIEW
Figure large
optics
fabrication
close
to its final
transferred ishing its final
Here
surface
facility.
hyperboloidal
to P-E's
facility.
2-22
Fields
quality.
The
AXIS
INTO
of View,
FORWARD PAGE)
InstrumentsSensors
Once
it was
tance
shape,
it was
known of the
computer-controlled the mirror
IMAGE
LOOKING
+V1
CAMERA
pol-
was polished largest
to
deviation
at the
Figure
the
The primary
States, would
mirror
was
the
size
of the
United
the highest mountain or deepest valley deviate less than two inches from the
surface.
being
ground
num ride,
and only
a protective 0.1
and polished,
with a reflective and
layer 0.025
respectively. The fluoride minum from oxidation
the glass layer
sur-
back
85%
mirror
right
mirror
through
the
and
also
by three
of the
glass
for lateral
spec-
visible
light.
mirror.
is mounted
to the
line
ultraviolet for
the primary
a set of kinematic
penetrate
face was coated
in the
over
shows
attach
straint, After
2-26
through ages
and
emission
The reflective quality than 70% at 1216 ang-
(Lyman-Alpha), range,
from perfection anywhere on the surface of the mirror is less than half a millionth of an inch. If primary
hydrogen
as Lyman-Alpha. mirror is better
stroms tral
important
to the main ring
linkages.
The
link-
by three
rods
that
glass, pads
for axial bonded
conto the
support.
of alumi-
of magnesium
fluo-
micrometers
thick,
layer protects and enhances
the alureflec-
2-21
2.2.1.2
Main
Ring.
The
main
ring
structure
encircles the primary mirror, the main baffle
mirror; supports and central baffle,
the
integrates
metering
truss;
and
the and
the elements
--
SECONDARY MIRROR ASSEMBLY GRAPHITE METERING
EPOXY TRUSS
BAFFLE
SUPPORT
SYSTEMS
MODULE
SENSOR
(3)
PLANE STRUCTURE
ALUMINUM MAIN BAFFLE
SCIENTIFIC INSTRUMENT
ELECTRONIC
BOXES
PRIMARY
MIRROR
MAIN
RING
ED
HEAD
STARTRACKER
RADIAL
Figure of the telescope made of titanium, an
outside
Figure
2-27).
a kinematic
2-23
OTA
to the spacecraft. The ring, is a hollow box beam 15 in.
weighs
1200 Ib (545.5
diameter
of
It is suspended
9.8
ft
kg), and has (2.9
inside
m)
(see
the SSM by
support.
head
Reaction is a wheel
ter.
behind
It radiates
supports
the main
ring,
reaction forming
spanning
plate a bulk-
its diame-
2-22
out
the central
is to carry
an array
warmth
to the back
taining
its temperature
beryllium Plate. The of I-beams
(1)
Components
also 2.2.1.3 structure
(3)
SCIENTIFIC
INSTRUMENT
(38 cm) thick,
(4)
tors
from baffle.
attached
ring,
Its primary
of heaters, of the primary
radiate
mirror,
and stiffness,
the
primary
main-
Made
of
the plate
a set of 24 figure-control to
which
function
which
at 70 degrees.
of light weight
supports
a central
mirror
actuaand
arranged around the reaction plate in two concentric circles. These can be commanded from
the ground, if necessary,to make small corrections to the shapeof the mirror. 2.2.1.4
Baffles.
vent
stray
sun,
moon,
light
The from
and
baffles bright
earth,
of the objects,
from
OTA such
reflecting
MIRROR CONSTRUCTION
pre-
FRONT FACESHEET
as the
down
the
telescope tube to the focal plane. The primary mirror assembles includes two of the three OTA baffles. INNER EDGEBAND
Attached outer,
to the front main
baffle
is an aluminum
(2.7 m) in diameter equipped stray
face of the main
and
light.
The central
in shape,
and
the
cylinder,
9 ft
15.7 ft (4.8 m) long.
with fins internally
conical
ring,
to help
baffle
,LIGHTWEIGHT CORE
It is
attenuate
is 10 ft (3 m) long,
attached
to the
,OUTER EDGEBAND
reaction
plate through a hole in the center of the primary mirror. It extends down the centerline of the telescope
tube.
painted with reflection. 2.2.2 The
The
flat black
Secondary secondary
the front
face
secondary
baffle paint
Mirror mirror
interiors
were
to minimize
light
Assembly
assembly
cantilevers
of the main ring and
mirror
REAR
at exactly
supports
the correct
I
off (THE
the
MIRROR
MIRROR
,,_,_,_-
MAIN
_-PRIMARY
_'ACTUATOR
_
7971
GLASS)
T _//_/_[O_YY
The
(see
secondary
mirror. within
of an inch
This position a tenth of
whenever
The
assembly
subassembly,
a light
graphite-epoxy
structure
/
CODE
Primary Mirror Construction
is operating.
of the mirror outer
J
2-25
one-thousandth
MIRROR
scope
BAFFLE
CONNING
in front of the primary must be accurate
BAFFLE
_zdl//l/I/lll/i./l/I/I/l_
CENTRAL
OF
EXPANSION--SILICA
ASSEMBLY
"_
k
MADE
position Figure
PRIMARY
IS
ULE--ULTRA-LOW
mirror
truss
and an support
2-28).
subassembly
contains
the
_..,,_
mirror,
which
is mounted
on
three
alignment actuators controlling and orientation of the mirror. All Figure
tele-
is composed baffle,
metering
Figure
the
2-24
The Primary Assembly
Mirror
within
the central
truss support.
2-23
hub
the are
at the forward
pairs
of
position enclosed end of the
BASE
PLATE
- ACTUATOR
PAIR
SECONDARY
MIRROR
)NDARY MIRROR BAFFLE
/ I ACTUATOR PAIR
CLAI FLEXURE
Figure The
2-26
secondary
10.4X,
mirror
converting
ing rays prime
from
focus
the center through
Pn'mary
f/02.35
to a focal
of the primary central itself
coated
is a convex
with
is even
ratio where
to the
aluminum
right position The
greater
than
picked
point.
sensors
its
The
mand
can be adjusted
to align
the
secondary
principal
ondary
T CENTRAL
INTERCOSTAL RIB (48)
\ N
BAFFLE
/-\
J
mirror
__¢__
--
rings
and a central
com-
BRACKETS
(5)
RAO_LI-B_M (_s) _ROL
ACTUATOR
FLEXURE
_i_..._._/_:_
_
_"_-_
--_
ft
mirror. (2.7
chosen
m)
for
to nearly ary mirror
zero. must
attached
tiny
stiffness,
stay perfectly accurate when
truss,
a
for the seca
and
graphite
Graphite
light
was
weight,
and
expansiveness
This is vital because
mirror,
sec-
to three
is
structure.
the structure's
(2.5 micrometers)
the
16 ft (4.8 m) long
diameter,
its high
the primary
(24)
in
of
structure
truss,
epoxy
it reduces
the second-
placed
relative
to
to within
0.0001
in.
the telescope
operates.
at one end to the front
face
of the main ring of the primary mirror assembly. The other end has a central hub which houses
--
the secondary
_
tion (MLI) 2-27
data
sensors.
is the metering struts
support
The
fiber-reinforced
cal axis. Figure
system's
guidance element
48 latticed
The truss is attached AXIAL
control
fine
assembly
primary
in just the
FIGURE
quality.
from
structural
with
because CENTRAL raNG--N
image
calculated
optical
in the
cage
by ground mirror
by the
Assembly
perfect
are
located
ondary
actuators
to provide
surface
9 The
up
Mirror
12 in.
magnesium the
Secondary
adjustments
it passes
from Zerodur and
2-28
system
focal
and
convex
Figure
toward
hyperboloid,
and is made
of
converg-
it back
mirror,
baffle
It is steeply
accuracy mirror.
a magnification
the primary-mirror
(0.3 m) in diameter, fluoride.
Mirror
of f/24 and sending
the
The mirror glass
has
J
The Main Ring and Reaction Plate
temperature Farenheit
2-24
mirror
Aluminized material
and mylar
baffle
along
the opti-
multi-layer
insula-
in the truss compensates
for
variations of up to 30 degrees when the HST is in earth shadow so
the
primary
aligned.
See
support The
and
secondary
Figure
2-29
mirrors
for detail
from
remain
on the truss
baffle
secondary
extends
reduces sources
mirror
almost
subassembly
to the primary
the stray bright-object outside the HST field
2.2.3
Focal
trackers
2-30).
structure.
conical
star
the sun in space,
Plane
Structure
light
mirror.
light from of view.
and
plane
structure
(FPS)
rate
replacement mal isolation
the
sensing
It also provides
units
bright
The
structure
(3.04
m) long
is 7 ft (2.1
m)
and
over
weighs
square
is a large optical
extreme
locations,
thermal
because
stability
and
and
strong.
The
FPS
supports
for
orbital
guidance
units
The
-V3 side
of the
structure,
10 ft (545.5
the Sis away
used
during
The focal
plane
face of the points ment
structure adjust
the
has
light-
metallic
replaceable
cantilevers
attached to
The structure
for
stiff,
have
maintenance.
main ring,
that
distortions.
it must be
and
FGSs.
by
1200-1b
mounts
and
ther-
kg). It is made from graphite-epoxy, augmented with mechanical fasteners and metallic joints at
Assembly
supports
Figure
for in-orbit
It
weight,
and physically
(see
the facilities
bench which aligns the image focal plane of the HST with the scientific instruments and fine sensors
fixed-head
of any of the instruments and between each instrument.
strength-critical The focal
supports
fine
and latches location so
exchange
scientific
equipment
easily
flexible
eliminate provides
guidance
guide-rails mounting
off the aft
at eight
thermal a fixed align-
sensors.
at each Orbiter
It
has
instrument crews can
instruments
and
other
in orbit.
PRIMARY MrRROR RING
MAIN
-\'_
--
,
/¢
"_'_"'_
/ffA
FOCAL
PLANE
STRUCTURE
/Sl
N_
CONNECTOR
" __EM
/
_',_,,/_
HANDLES--" FIXED-HEAD STAR
TRACKER
,,..-"r"
1 _- SI (3)
LATCHING MECHANISM
Figure
2-29
Mirror Metering Structure
Truss
Figure
2-25
2-30
Focal
Plane
Structure
V2
2.2.40TA
Equipment
Section
bilization.
There
sembly The
equipment
scope
section
Assembly
is a large
compartments on
the
mounted
forward
2-31).
control
guidance
electronics,
ics, optical section
storage,
unit.
bays;
(see
Figure the
are
fourth
doors for easy access, for the electronics, and for thermal control.
electrical
power/thermal
control
cabling heaters
electron-
distributes
power
from
the
SSM
electric
power
subsystem
to the
OTA
sys-
tems.
The
controllers
temperatures. from also
system
to regulate
This
prevents
cold space temperatures. collects thermal sensor
mission
the
mirror
unit
electronics and
telemetry
interface
its response
to the unit.
to the
commands electronics
go through
com-
from
the
the
data
The
optical
control
trols
the
white
light
electronics
optical
control
(OCE) sensors.
interferometers
quality
ground
which
of the OTA
for analysis.
each FGS, OCE.
but
unit con-
and are
are the
send
There
all OCSs
These measure the data
is one
OCS
controlled
to for
by the
uses mirror
The data interface
distortion
The EP/TCE data for trans-
units
interface between
and
the
unit (DIU) is an electronic the other OTA electronics
HST
command
and
telemetry
system.
to the ground.
three
fine guidance
provides
power,
each
guidance
fine
performs faces
monitors
Positioning
2.3 The
control
and
mand.
the
system
thermostat
(ACE)
sensor.
have
ics (EP/TCE)
temperature-control
as-
to the 24 actuators attached to the primary mirror and six actuators attached to the secondary mirror. The ACE selects which actuator to
optical The
guidance
the command
ground interface
for equip-
All bays
actuator
move,
equipment
used
support.
fine
electronthe
OTA
The
provides
power/
and
The
of
spacecraft
control
seven
for
set
system,
for each
electronics
Tele-
electrical
electronics,
two
outward-opening and connectors and insulation
OTA actuator
interface
has nine
ment
the
SSM
electronics
control
data
Optical
semicircular
of the
the
thermal
the
outside
shell
It contains
DMS
for
is a guidance
electronics
commands, sensor.
computations telescope
The
electronics
pointing
line-of-sight
pointing
to unit
and inter-
system
for efand sta-
The
LOOK,,G_ORWARD
cumference
Figure
__
2-31
guidance
of
between
Figure
long,
3.3
the
2-30). ft (1
sensors
intervals
enclosure
and
sensor
wide,
kg). Perkin-Elmer FGS
plane
frame
Each m)
the
are
the
cir-
structure, main
ring
is 5.4 ft (1.5 m)
and
made --
(FGSs)
around
focal
the structure
(see
used
_/__//
-7
SENSORS
weighs
485
lb
called
a
the sensors.
sometimes
radial -- actually guidanceare sensor sensors bay and aremodule a elements wavefront of sensor. the houses OCS, The awhich wavefront
-w
ON
fine
at 90-degree
Each
V ---_-v2
{3OORS
three
located
(220
MLI
GUIDANCE
units
telemetry
for the sensor
with the spacecraft
fective
(FGE)
and
FINE
to align
and
optimize
the optical
system
of
the telescope. _
]
i
_
;
\
,_'_--"'-
The ability of the HST to remain pointing distant target to within 0.007 arcsec for
FG;_{_mm_mm_GE
The
OTA
Equipment
Section
periods
2-26
of time
is due
largely
to the accuracy
at a long of
the
FGSs.
The
and measure
guidance
sensors
any apparent
cy of 0.0028
arcsec.
lock
motion
That
on a star
to an accura-
is equivalent
from New York City the light on an aircraft flying
direction the
galactic
two sensors
motion of a landing over San Francisco.
lock on a target,
the third can
the star.
in Chapter
3.
FGS
The
fine
Composition
can be anywhere
guidance
structure
housing
servos
the image,
beam
tubes.
The
adjustment alignment
has
a large
for
and
field of view point
the
lenses,
to fine-track
splitters,
and four
photomulti-
with
track
of mirrors, prisms
entire
(60
of a large
the image,
required
cise
consist
a collection
to locate
plier
sensors
to move
the
a target
star.
armin
2) field
stars, used
mechanism
and
makes
the
HST into preEach
of view
sensor
to search
a 5.0 arcsec-squared
by the detector
prisms
to pin-
in pairs
to aim
star.
The
FGS
within
fine
guidance
the Space System,
work
The
Guide
Telescope. developed
alogs
and
tion
target
First
one
charts sensor
ignated
guide
stars
and
star.
The
located,
each
to find
will search
Selection
Institute,
near
it easier
the first sensor sensor locates
guide
Star
by the Science
to make
star. After the second target
sensors
cat-
observathe
target.
for a target
guide
locks on a guide star, and locks on another
guidance keep
observation target in the lected scientific instrument.
stars, the
once
image
aperture
of
of the the
"science"
of view has the ture distortions. view was finding
chosen
field.
se-
This region
secthe
of the field
greatest astigmatic and curvaThe size of the FGS field of to heighten
an appropriate
guide
can
move FOV
tectors
ters
the probability star,
even
of in the
2-27
within
to keep
position
the
the star
its line using
field
signals
of
so the to find
FGS
has to
to the HST image
of sight
a pair
60
star
this field,
the star, error
has
guide
in that
per-
anywhere
of star
selector
of as an optical in a North-South
other moves FOV (5 arcsec
to any
Encoders the exact
FOV
The
Each may be thought -- one servo moves
East-West. They 2) of the FGS de-
in the
whole
FGS
within each servo system coordinates of the detector
field.
send back field cen-
at any point. there
is often
some
uncertainty
about
the
exact location of the guide star in question, the star selector servos can also cause the detector to execute a search most probable guide a spiral
pattern,
of the region around the star position. It searches in
starting
at the center
ing out until the detector seeks.
Then
"finds"
the detectors
into "fine-track"
mode
about
the
The
position
and
detectors
ometers
of the
control
hold
themselves
called
to go
the star
image
to the spacecraft
are a pair
Koesters' tubes.
wavefront
the interferometers edge
star it
of view, while the send information
star
prisms, Each
in one axis, so two are needed.
one
the guide
system.
photomultiplier incoming
and spiral-
are commanded
exactly centered in the field star selector servo encoders pointing
Each fine guidance sensor uses a 90-degree tor of the telescope's field of view outside central
des-
to move
direction; the steer the small
Since The
found
it and send
its large
servos. gimbal
FGS
anywhere
Having onto
telling how fectly still.
and Function
Each available.
will "look"
"lock" FGS
of view.
arcminutes
the
2.3.1
-- near
poles.
field
square interest
is discussed
population
An FGS "pick-off" mirror intercepts the incoming stellar image and projects it into the sensor's
measure the angular position of a star, a process called astrometry. The astrometric function of sensors
star
to seeing
large When
of the lowest
of the
from telescope
detector
on the
guide
the wave entrance
to
operates
Operating
the distant
compare
of interfercoupled
star,
phase aperture
at
with
the phase
phases
are
at the opposite
equal,
Any phase which must
the
star
edge.
When
is exactly
difference shows be corrected.
the
the
centered.
a pointing
FGS
shown
turn,
or "fold,"
thing
inside
the
The
the
the telescope's All optical
FGS
in order
enclosure,
wavefront
astigmatism
elements
are
ature-controlled
and
bench.
Figure
2-32
Figure
2-32b
OTA.
ror, ror.
field curvature.
mounted
diagrams
on a temper-
used
composite
cutaway the
pickoff
are, like the These,
The
mirror
FGS
to compute
detec-
however,
imperfections
the alignment
contain
are
in the through informa-
of the secondary
and the optical quality The data is telemetered
system. actuator re-orient is a simplified
sensors
interferometers.
tion about
to correct
graphite/epoxy
optical
the
to fit everyand
to the
designed to measure small imperfections stellar wavefront result from its transit
from telescope to detecoptical elements which
beam
close 2-32a.
error
tors, Along the optical path tor, there are additional
enclosure
in Figure
mir-
of the primary to the ground
any corrections
to the
mirand
optical
These corrections are converted into commands and sent up to the HST to the OTA.
of the FGS;
optical
path. The wavefront sensors are very precise optical instruments and are mounted to a machined
2.3.2
Wavefront
Sensor
be-ryllium optical ture-controlled, to
The optical control system is a system of three wavefront sensors and control actuators which
the
FGS
the
wavefront
enable
once
the
ground
alignment
controllers of the
to correct
telescope.
and adjust
They
which
that is temperastability. Unlike
will be used
sensors
the OTA
month
fit inside
sensors,
bench maintain
will be used
has been
aligned
constantly, infrequently
during
the first
in space.
ENCLOSURE r--
ASPHERIt MIRROR
COLLIMATING
FGS
ST
"-"
/
F
COLLIMATOR _FIRST STAR SELECTOR
./
PINHOLE/LENS ASSEMBLY (4)-
/
OTA_
/
/
/
// I'
/
REFRACTIVE GROUP F SECOND STAR
/SELECTOR
-_
LI
LI /
- STAR SELECTOR
- J'I
i M"F'O'S
DOUBLET LE N S (4)
r /
I\11 _ CORRECTOR
I
FIELD LENS AND
f"
KOESTE_
"--
DEVIATION PRISM
OPTICAL
v _k
DOUBLET_ _ FIELD STOP "-'__"_'_)w_.,¢_
PHOTOTUBE _.
II .,_
PRISMS
, ,
DES_._...M ERS IS _
WPUPIL
_)1_ ROTATED 90 °
I
L
BENCH
FILTERS(5), PICKOFF
MIRROR
Figure
-J
2-32a
FGS
Figure
Cutaway
2-28
2-32b
Optical
Path,
FGS
2.4
SOLAR
ARRAYS
The two solar Space
arrays,
Agency
designed
and
built
by the European
by British
serve as the main source Hubble Space Telescope. operate
the
arrays,
maneuvering
the
of power for The STOCC
extending
the
spacecraft
sunlight on the arrays. to energy and stored
Aerospace, the will
panels
to focus
SOLAR
and
maximum
PRIMARY
/
arrays solar
two-stem sette
are two rectangular cell blankets fixed
frame.
in the
CASSETTE/
The blanket
middle
of the
The
wings
are
on
arms
wings between
unfurls
wing.
at each end of the wing stretches and maintains tension.
that
of a
from
a cas-
A spreader
bar
length
of the
(4.8 m) (see
Each
wing wing,
small
that
attached
connect
mesh
tightly
panels,
roll
out made
wiring
layer
500
weighs
ten
are
arm,
to a drive
up
of Kapton.
is 15.7 ft
m) long
on each
the
kg)
are and,
and
cells with
is covered
blankets
by
are
less
so they
can roll
stowed.
Each
BAR
Solar
Array
2-33
The
primary
solar
array
deployment
is
wing.
Each
mast when
and supports erect.
mary and secondary the drive mechanism,
the side
mechanism
An astronaut
of the
raises
the
SSM
to a
to the teleone for each
has motors to hold
can raise
if the drive on
the
the
to raise mast
power
the array
fails.
Using
deployment
hand-cranks latches.
mast
the
in place
mast
manually,
a wrench
drive,
the
Once
the
solar
deployment
Subsystems
are
Wing Detail
mechanism
from
MECHANFSM
the
after
fitting
astronaut
releasing
the
wing
at full extension,
arrays
BAR
up
8.2 ft (2.5 m) wide.
for the solar
Solar Array
mast
Each
array
is raised,
mechanism
unfurls
wing
the pri-
the cassette
cushion
to protect
deployment mechanisms, and the electronic control
assembly.
ket, stretch, wing pletely
2-29
drum
the blanket,
applies
tension
and
transfers
or part
The
data
and
blanket
blan-
mechanism and
as-
panels,
motors
a
and
rolls out the blan-
evenly
way. The
secondary wing
to hold solar
The assembly
assembly.
the the
has a secondary
sembly:
subassemblies. The subsystems
SPREADER
standing position perpendicular scope. There are two mechanisms,
kets. 2.4.2
PULLEY
CASSETTE STEM
of The
solar
surface,
that
The
half
cassette.
of 2,438
thick
wings
17 lb (7.7
40 ft (12.1
five
underneath
the
drive
fiber/Kapton
micrometers
when
and
from
SPREADER
Figure
2-33).
to a glass
another than
has
panels
silver
cassette, Figure
BISTEM
out the blanket
assembly on the SSM forward shell at one end and to the cassette on the other end. The total
the
//,/_
Configuration
The solar retractable
DRIVE
The sunlight is converted in batteries until needed.
DEPLOYMENT
2.4.1
ARRAY
so
the
power can
secondary
blankets along
roll
out
the com-
deployment
mechanismalso has a manual override (see Figure 2-34).
The
electronic
monitors
control
all solar
assembly
array
system
controls
and
functions.
It con-
trols the primary and secondary deployment mechanisms and the solar array drive. FITTING
FOR
MANUAL
2.4.3
DEPLOYMENT
WING
MAST
SECONDARY
Figure
2-34
DRIVE
Fitting for Solar Array Manual Deployment
Operation
When
the
Hubble
cargo
bay
of the
stowed
against
against
the
In this
26 in.
(65
Figure
2-35). the
into
orbital
unfurls The solar array drive rotates the deployed toward the sun, turning in either direction. drive Each
array The
and
a brake
to keep
the
array
the
in a
possible
position
drive
has a clamp
mechanism ber
if opened.
to jettison
necessary
arrays
the by
light just (see
Telescope extends
ground
and
command.
and
solar
latched and
extend
Space
power
are
surface
STOCC
unfurled
absorbing
electrical
shell
SSM
facing
energy
the
and pass-
subsystem.
INSTRUMENT AND DATA HANDLING
This allows solar
Scientific
Instruments
Control
Handling unit (SI C&DH) ic instruments. It:
ring that acts as a release
the entire
by the
are
arrays
for maintenance. The
Each
the
arrays
SCIENTIFIC CONTROL UNIT
2.5
fixed position if the HST moves around in orbit. The drive can move and lock the solar array into any
solar panels
ing it to the
the the
places
position,
sun, they begin
is at the base of each solar-array mast. drive has a motor that rotates the mast on
command,
Orbiter
the
When
forward
position from
is in the
solar
with the masts
of the
cm)
Telescope the
the SSM
sides
shield.
Once
Space Orbiter,
controls
and
Data
the scientif-
a crew mem-
array
•
if deemed
Watches keep
STOCC.
all scientific
them
instrument
synchronized
and
systems
working
GRAPPLE FIXTURE RECE PTACLE --7 /
/-" SDM STOWAGE /HANDLE
/ =_' ./--
/
/' .-. ...... I_tlr
....
_--_--':'-
DIODE BOX SDM MANUAL
,,rr
\
A
I
-
Figure
--_
::
2-35
:
Solar Array
....
_-'-I
Wing
2-30
_'_;_1
Stowed
....
Against
[-----,t----Lc.l,_ir....l_
SSM
26.05 In. MAX.
to
Works with process,
the
data
management
unit
and
communicate
all
format,
to EVA
sci-
'-'HANDLE
ence and instruments
engineering
data
created
by the
Al18_ Al16_,,\
AlO, 2 CPMS
It was built
by Fairchild
Corp.
IBM.
and
2.5.1
SI C&DH
Camera
ponents tray
is a collection
and Instrument
of electronic
com-
replaceable
unit
to an orbital
mounted
on the door
equipment
section.
of bay
Small
ments.
The
make
C&DH
are the NASA model
face
I (NSSC-I);
(STINT)
puter;
two control
two
memory, lines
data
and
SI C&DH
so the system
failure.
See
C&DH
components.
Figure
the
formatter unit
unit
(PCU);
(RIU);
and
various
communications
by bus
coupler
units
are
dupli-
components
can recover
from
2-36 for the
layout
NASA
Figure
any single
spacecraft cessing
computer
model
unit module each holding
embedded
software
and operation for individual of
the
of the SI
programs ment data.
monitor
and analyze
standard
a central
and eight
8,192
18-bit
program
(the
It moves
data,
programs scientific
processing
I has
(CPM)
modules,
runs the computer.
The NASA
pro-
memory
words.
One
"executive") commands,
(called "applications") instruments in and out unit.
and control
The
application
a specific
and manipulate
2-36
SI C&DH
TRAY
Components
The memory stores operational execution when the HST is not
commands in contact
the ground system. Each memory five areas reserved for commands unique
to each
scientific
The computer
instru-
the collected
for
around
failed
2.5.1.2
for with
unit also has and programs
instrument.
is the
the computer formatter.
science
requests
from
or
for
the
working
equipment. Unit.
The
standard
communications
SI C&DH
data formatter.
between
unit/science
Unit/Science
of the
interface
bridge
and the control
Control
heart
be reprogrammed
future
STINT
board
Data is the
It formats
data
Formatter.
control
unit/
and sends
to
the right source all commands and data passing between the ground command, the data management unit, the NSSC-I computer, the SSM, and the scientific instruments. The unit has one microprocessor matting The data and ples
2-31
can
ground
2.5.1.3
Computer.
UNIT
BCU--'
The 2.5.1.1
REPLACEABLE
_
com-
processor
command
The
SI
com-
control
units
connected
the
INTer-
for data
central
a power
interface
(buses),
(BCU). cated
two
(CPMs);
remote
units
unit/science
units;
up
spacecraft
two STandard
circuit-board
(CU/SCF) modules
that standard
,-_. _
mod-
system, are conscientific instru-
components
JT._
A240
10 in the
remote
ules, also part of the SI C&DH nected to each of the individual
puter,
._
Components
attached
and
SSM
/
A221
_;I
The SI C&DH
J
each
for the
control
and for-
functions.
control
unit
requests, system
science
signals
of system
receives and
signals
ground and
engineering
information. are
commands,
"time
data,
Two examtags",
clock
signals
that
synchronize
the
and "processor interface munications codes.
The
unit
transmits
after
formatting
entire
tables"
(PITs),
commands
them
isolates
spacecraft, or com-
and
so the specific
requests
destination
mands
use
lates mat.
16-bit
signal words
words.
The
should
fail. The
orbital
replaceable
2.5.2
Operation
The SI C&DH
unit can read the signal. For example, ground commands and SSM commands are transmitted with different electronic commands use 27-bit
tem
command 2.5.2.1
formatter
tells
trans-
each command signal into a common forThe control unit also reformats and sends Analysis
of this
handles
System systems
trol
Power
Control
unit distributes
The
and switches
the components
of the SI C&DH
lates
as required
the
power
computer ously
memory
need
power
conamong
unit. It modu-
by each
boards,
+ 5 volts (V),
power
unit.
for example, -5 V, and
The
2.5.1.5 ule
Module
units transmit
Units.
commands,
Remote clock
mod-
and other
modules
do not send
science
Command the flow
C&DH.
Commands
data.
the drawing) face (ground unit (SSM
There
storage.
Each
2.5.1.6
and power units in contains a remote
Communications
expander Buses.
units. The
SI
C&DH contains data bus lines that pass signals and data between the SI C&DH and the Sis. Each
bus is multiplexed:
messages, requests transmits
commands, to the
and
module
requested
one
line sends
all monitoring
inter-
to every
40
devices
it to the NSSC-I
The
computers
pro-
Any failure
indi-
tests could provoke a (see section 2.1.7,
system
engineering
data
units,
and a reply
information
and
Processing. of commands enter
data
the
Figure 2-37 within the SI SI C&DH
formatter
(bottom
conright in
through the command data intercommands) or the data interface commands).
The
line
"Time-tagged"
the computer's
one dedicated the SI C&DH.
unit and up to two
scans
information.
2.5.2.2 illustrates
also
interface
msec
above).
are six remote modules in the Space Telescope: five attached to the scientific instruments, and to the control Each module
At regular
500
constant situation
instru-
control
unit checks
and reformats the commands which then go either to the remote modules or to the NSSC-I for
system signals, and engineering data between the scientific instruments and the SI C&DH. The
cated by these "sating hold"
data
whether
every
computer.
the
etc.),
Engineering
data and passes
trol unit/science
are kept straight.
Remote
or store
sys-
checks,
vari-
+ 12 V; the
control unit, on the other hand, requires + 28 V. The power control unit makes certain that voltage requirements
cess
instrument
system
are functioning.
for engineering
Unit.
scientific
computer
sec, the SI C&DH
unit is on the
tray.
Monitoring.
from
unit
and data processing.
monitoring
vals, varying
interface
coupler
(timing,
or to the SSM 2.5.1.4
unit
processing,
the
ment
if the remote
SI C&DH
monitoring
formats. Ground and SSM com-
engineering and science data. data is an NSSC-I function.
the module
follow
(top
right
in
of drawing)
is interpreted
as "real
time",
as
SI C&DH just received it. Many comactually are stored commands activated
by certain HST tion
memory
stored
this process.
command
if the mands
commands
situations.
is positioned using
Object
program
is activated.
The
systems
to
required
perform
when
SI C&DH such
the
observa-
Spectrograph,
whatever
by a command, to maneuver
example,
for a programmed
Faint
system
the
For
that activates
actions as the
are
pointing
the HST.
science
data back to the SI C&DH. A bus coupler attaches the bus to each remote module.
unit This
2-32
2.5.2.3 Science Data Processing. Science data can come in from all scientific instruments at
•
SI-UNIQUE MEMORY
COMMAND STORED MEMORY
I
I NSSC-1
STORED COMMAND OUTPUT SUFFER
1
MEMORY SI-UNIQUE
I
MEMORY SI-UNIOUE
I
MEMORY SI-UNIOUE
& STINT
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s,5
MEMORY SI-UNIQUE
m
I
0 0 • _
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0 111
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z o
_ WORD
ORDER,
l
TIMETAG,& I PARITYCHECKS I •
SUPERVISORY
BUS REFORMAT
TYPE CODE CHECKS
i
_
TO PCU
Figure
once.
The
control
unit
transfers
CUIs;_OCESSING
2-37
order, and
switching empty.
between
Each
them
packet
Command
incoming
ence data through computer memory called packet buffers. It fills each
sci-
locations buffer in
as the buffers
of data
goes
fill
from
to the
ground.
Data
the computer
ting,
the
stream empty
control of data,
buffers
synchronized ing codes noise)
returns
to the control
processes unit
must
either
called
send
full
link with the
unit
transmitbuffers
or
to maintain
SSM. Special
a
check-
and pseudo-random
to the data
as options.
|
_
LOGIC
Flow,
Figure HST.
2.6
I
ORDER
CHECKS
I
]/1
_:_ 1S-BIT J_r"
I
COMMANDS FROM CDI
COMMANDS FROM DIU
SI C&DH
2-38
for the
SPACE
flow
SUPPORT
of science
data in the
EQUIPMENT
One of the unique features of the Hubble Space Telescope is that it can be maintained or repaired
while
mission-life will capture
a continuous
packet
filler packets,
(Reed-Solomon
can be added
it. When
WORD
I
the
buffer to the NSSC-I for further processing, or directly to the SSM for storage or transmission after
PAR,.,
COMMAND
--
_'_ 27-BIT J %
See
2-3,3
in orbit,
considerably. and stand the
cargo bay, and any maintenance
which The HST
HST
extend
Space in the
its
Shuttle Orbiter
the Orbiter crew will perform tasks required. Maintenance
will require, at some time, exchanging scientific instruments major
will
components.
Major
replacing or and other space
support
FROM CU/SDF COMMAND PROCESSING DMU
TO CU/SDF
LOGIC
r-
TIME
[YH [yH I
CU/SDF
i
Figure equipment
used
during
Flight
The
FSS
Space
Support
during structure
beam,
platform Figure
The
reand
and
maneuvers
the
HST
that
holds
and
arm, which
the
rotates The
berthed or tilts it
FSS super-
components:
cradle
on
The
the out-
with a supporting
and
the
the
rotating HST
FSS
sits
(see
2-39).
cradle
is a two-thirds
to strengthen
in the
bay and
of the held
arm, at the end of the cradle,
oval
with supporting
the FSS. The
FSS is placed
Orbiter
perpendicular
in place
by latches.
beam spans and supports the cradle to mount flight equipment.
to the The and
latch is used
into
rotation
intermediate
toward
rotation
the
platform positions
Orbiter
platform,
to move
cargo
between
up to 140 bay.
the ends
of the
spacecraft. The platcamera embedded in
its base
HST
into the correct
tion on the platform.
The
rotation
platform
rotate
the
360*
once
it is latched
place.
The
units
to guide
The
that
platform carry
orbital
a Spacelab
to the
replaceable hold
two HST
maintenance
Replaceable
pallet to
contains
power
during
Orbital
tainers
the
telescope
equipment
orbital
Unit
with
can in
umbilical
and
support
procedures. Carrier
unit carrier
filled
posi-
(ORUC)
shelves
and
replaceable
is con-
units
(ORUs) for replacement or to be returned. The main components are the pallet, cradle, shelves, support
2-34
the
supports
cradle, holds the berthed form has a small television
2.6.2
beams Orbiter
(FSS), the orbital the ORU carrier,
major
a pivot itself,
The pivot
Structure
side horseshoe-shaped latch
the
operation.
has three
in the HST
are
in place
the servicing
Data
degrees
is a platform
Telescope
Flow of Science
maintenance
Flight Support Structure placeable units (ORU), crew tools.
2.6.1
2-38
structures,
and
latches
to
hold
the
2.6.3
Orbital
Replaceable
Space
Telescope
Units
BERTHIM3
t_TC_ES
FSS
ccrv PIVOT MECHANISM
L_III
designers
selected
modular
ST MAINTENANCE
HST components Orbital Replaceable which were critical as subsystems throughout Units, the
UMBI/ICAL
HST that ability analysis, designers might determined, degrade duringthrough the HST's reli-
I[_"_
STDEPLOY/RETURN
mission
UMB'L_AL
units -- usually a self-contained box with simple fasteners and connectors -could be might need replacing, they werethat designed as
LATCH aEAM _ll/Jt__..
lifetime.
replaced ---C_DLE
easily
replaceable
/ .....
Because
There
in
units
these
one
components
piece.
A
is in Appendix
are 70 ORUs,
list
of
the
E.
comprising
some
26 differ-
/ /
ent components
/
from
the
-- some
small
phone-booth-sized ORUs
are
arranged
tion options -.........
for the
duplicated
-- ranging
fuse
plugs
to
the
tele-
Faint
Object
Camera.
The
into
a series
of configura-
ORU
carrier,
and
servicing
j/
requirements
at the time
will determine
which
ORU option -- and which units in that option -- will be included on a maintenance mission. A Figure equipment has
2-39
within
the
closed-door
crew
aids
FSS
Superstructure
carrier.
The
compartments,
that
can be used
maintenance
(see
Figure
by the
carrier
also
likely which
tethers,
and
configurations
crew
during
2-40).
first candidate have a short
2.6.4
Crew
The
KEEL
LATCH--
k
\
bay, and and
SMALL
\
oRu
the
HST
CRADLE
_ _,_._.,_
FGS _
_
LOADISOLAT,ONJ_.. SYSTEM FLIGHT
and
override
standardized
Space
not HST
Station,
and
Orbiter
drives.
Tools
and
other
only
and
Vehicle. For example, share common features
move
the
for
the the
the
Space Orbital
grappling to promote
uniformity.
STRUCTURE -/ ../'\/'_.,,_ SUPPORT SIPE j / Nv2"_,._ 0 '_,,,.//_ ____,,_
Figure
the
them
equipment,
connectors,
the
extra-
to help
FGE
V\\"_
S,PE
manual
between
Maneuvering receptacles
2-41.
perform
tools
and
bolts,
were
but
many
Telescope
operate
Shuttle, SHELF
Space
equipment
hardware
_I._._
__
will
using
instruments
around
in Figure
astronauts
activity
replace
/SUPPORT /--KEEL LATCH
shown
Aids
Orbiter
vehicular C&DH-_
are
will be the HST batteries, lifespan. Four typical ORU
-J_>
BATTERIES "
\ _ _
"--SPACELAB PALLET
DIRECTION
2-40
Typical
ORU
Configuration
2-35
To get
around
the
HST,
feet
of handrails
that
For
visibility
rails
the
the
crew
encircle are
addition,
the crew can hold
trunnion aft.
bars,
will use
the
painted onto
and scuff plates
guide
225
spacecraft. yellow. rails,
that are fore
In the and
BATrERIES
-_
SINGL
RADIAL FGS MASS SIMULATOR
R FGS
SI MASS
SIMULATOR)
Figure
2-41
Four
ORU
Payloads
There are also portable handhold plates that the astronauts can install where there are not
consuming.
permanent handholds, ance sensors.
sockets
Another use
tool
is depicted
ber
will
crank
a
the antenna
er fail for the mast is
available
if
foot
restraint.
4, in section
procedures.
units have
Other
and on
a jettison the
to the HST. ratchet drives.
crew tnemto
masts,
manually
should
A power
hand-cranking
2-42
they will use suits and tie
Each
wrench
and array
4.3 on
See Figure
are working to the EVA
Its
wrench is
too
powalso time-
2-36
hand
tools
handle,
aperture
wings so the crew from the HST.
in Chapter
the astronauts to hook tools
replacement
as on the fine guid-
is the portable
HST maintenance for an illustration.
While tethers
such
lights
door
include which and
portable attaches solar
can push the equipment
to array away
Section THE
The
scientific
Space
Telescope
(FOC), the
instruments
the
are
Faint
Goddard
(GHRS), and
the
PC).
FOS,
GHRS,
a
scientific
scientific and HSP optical
axis so that
can
fit into
the
focal
parallel
•
to •
apertures. dimensions
are placed
and the three just
forward
of the focal
sensors
plane
in the optical
the incoming entrances.
No scientific in the
focal
plane,
instrument Space falls
make
Telescope directly
tics and
because
detection
small
of the beam.
instrument
This
ferent
filters,
entirely
devices
gratings,
separate
instrument The
astronomy
is called
or
optical
to break
filters,
gratings,
for the GHRS
team
the
can
prisms
systems light and
the
locking
in the selected
other
them instru-
target.
and positioning
and
onto
the appropriate
devices
needed
fil-
to modify
the
light.
Exposing the instrument's detector light as long as needed to make the measurement.
•
Processing transmission
•
Analyzing for further
the collected to earth.
to the desired
information
the data and using observations.
for
the information
of each astronomical
scientific targets,
up the rest of this chapter.
The
tion of the
sensors
fine
guidance
instrumake
astrometric
func-
is included.
light
The
optarget
into other
are Operated
select --
THE FAINT
OBJECT
CAMERA
the FOC,
more
than
the other
use the
optical
resolution
objects
in deep
space
fore.
observing
and
aperture
to acquire
Selecting
3.1
acquisition. The
FGSs.
a large
Physical descriptions ment, and possible
But each
so the incoming
system.
stars
of:
size of
to adjust
specified
the
Using
consists
the pick-off
calculations
the
and
of data.
of
all of the light
of the
position
onto
part
respective
or because
up only part can
their
receives
aperture
pick
to deflect
into
instrument
the instrument mirrors
path
light
mechanics
collection
•
struc-
ture, at right angle to the optical axis. These four radial instruments rely on pick-off mirrors positioned
using
incoming
structure
fine guidance
process guide
ters
interchangeably.
The WF/PC
the
Control
unit's computer. own small com-
instrument
process
Selecting
ment
the incoming
plane
Instrument
(SI C&DH) have their
operate
and
The operation
the FOC,
-- are located
will fall into their entrance instruments share the same
so they
sensors
--
that
monitor
astrometric
instruments
Scientific
(WF/
guidance as
puters
(HSP),
•
the telescope's images These
Spectrograph
role
in the
& Data Handling Other instruments
(FOS),
Camera
fine
embedded
Camera
Photometer
Field/Planetary
(FGS) have instruments.
of the
Object
Resolution
the
INSTRUMENTS
in the Hubble
Spectrograph
Speed
addition,
Four
Faint
Object
High
Wide
In
the
High
the
placed
SCIENTIFIC
3
The
FOC
of the HST
more
or
even
able
-- within
one
FOC
to detect
examine
mechanical
and
by software
Solar
3-1
the light
will study
a spectrum.
System.
locate
and
to record
than
to capture
will
ever
be-
celestial
to 28my, which is so observatories are not from
the evolution
galaxies
possibly
clearly
will be able
lights with a magnitude faint that ground-based
dif-
instruments,
faint
planets
those
images.
of star objects existing
The
formation,
like quasars, outside
our
3.1.1
Physical
Description
secondary then
The FOC
was designed
by the European
in
West Germany and British England. Its physical dimensions
Aerospace in are 3 × 3 × 7 ft
used
(0.9
size
(ESA)
and
built
× 0.9 x 2.2 m),
phone has
booth; four
structure and
roughly
it weighs
major
the
about
The
houses
bench
head
assembly
that
supports
mechanical
equipment.
assembly handling
holds the equipment
elements.
main
optical
the
The
bay
and control.
of the
photon-detection
system,
data-processing
elec-
The
major
Figure
After
supply
the HST is positioned
light,
is focused
which
channeled
consists down
image
of many
one
At the end of the the FOC detection recorded
on the FOC
is placed
and can be intensified data is transmitted
3.1.1.1
Optical
FOC
using
consists
of two
optics
systems
incoming
light
FOC
aperture
scope
that
reflected
data
system
independent
in the
travels
through
into a small
a primary
same
that
out
light obser-
a mirror
of light coming
way:
the
the field
the
same
from
on
a cali-
light and geometby the FOC can
the
of
HST
because field
allows
the
objects
only 0.01
globular
on
ratio
the
FOC
to
which
apart.
the
stars
appear
It
can in-
is a tradeoff, system
(22 arcsec)
distinguish
that ground instruments between them.
Both
in the path
f/96 optical
arcsec
produces
resolution.
There
at best
for studying cluster,
main-
of f/24 four-fold,
inserted
of view,
while
system
best angular
up to f/288.
narrow
requirement
This
focal
device
that ratio
option
resolution.
System.
Telescope's
a special
of view light
spectral
increases crease
ratios,
has a 2, but it
between This
two
is a crucial
within
a distant
so close together cannot
distinguish
selected
Cassegrain
concave
length length,
a shutter
is closed,
to visible produced
the Space and
systems, focal
to the f-stops
telescope.
focal
systems there is a zoom
optical
The 1'/96 Optics
an image
optical
operate
for
optical
physical
has
the shutter a beam
doubles
taining
store
for the larger ratios.
is like the main from
that
is
pathways.
into
are similar
except
and
In both
The
photons,
in a science
and
the
FOC's
aperture
The FOC response ric light distortions also be determined.
each photon enters and is detected. The
apertures
These
cameras
energy
The
increase the
system
When
however,
System.
two different
f/96 and f/48. earth
in
aperture.
graphics
optic
it can reflect
by a longer exposure. The to earth, where it can be
enhanced by computer of the celestial object.
the
light from
of two optical
pathway device
beams
3-2 for
bration source down the optic path to measure the light-detecting capability of the detectors.
pictured
correctly,
mirrors
increasing
vations.
3-1.
an object
the
are
wavelength
Figure
wheels
remains closed, completely blocking until the FOC is needed for astronomical
for the detectors.
subsystems
folding
Each
dataThe
is composed
power
processing. filter
and
assembly
and
and
contain
onto the
move to adjust the focus, and correct for astigmatism in the HST telescope mechanism.
optical
photon-detector tronics,
See
plane,
and finally
enhancing
critical
studies.
without
The
electronic
data-processing and system
for
pathways
to isolate
The
elements an
on a different
mirror,
kg). It
loadcarrying
contains
tube optical
specific layout.
of a tele-
the optical
photon-detector
optomechanical
System
700 lb (318
subsystems.
assembly
the
by Dornier
mirror
a folding
detector
Space
Both
Agency
convex
onto
tele-
The
The light is mirror
block
to a
f/96
unwanted
coronographic
3-2
optics
have
two
light from fingers
special
features
to
the field of view:
two
in the
aperture,
and
an
OPTICAL
BENCH
OPTICS
PATHWAY
INCOMING
LOAD CARRYING STRUCTURE
Figure apodizer
mask
optical The near
can be moved
3-1
FOC
Major has
into the f/96
fingers the
can target
block
bright
of the
FOC,
can be detected is useful
ELECTRONIC ASSEMBLY
Subsystems a faint
companion
when
objects
that
so the
targeted
with less intrusive
observing
a bright
It is near
light.
star
the edge
the smaller
that
PLANE
_//_-, _L_t0_mm/
ST A_I /
_
of being
a
B_-__
device
finger.
that blocks
but includes The
apodizer
out stray light re-
off the secondary
support creases
structures. The Cassegrain system the focal ratio to f/288. This narrows
field of view even WHEELS
f/96 FOV
flected
olution FILTER
of the
coronographic
embedded telescope.
mirror
and
ST optical inthe
MIRRoRPRIMARY
/
/-
SM_RCRO(_g ARY
suspected
The high-resolution apodizer is within another miniature Cassegrain
are
is a masking ST FOCAL
BAY
planet.
path.
object This
which
PHOTON DETECTOR ASSEMBLY
FOLDING
needed
by brighter almost
to detect
ones.
The
only
able
one
but increases faint
FOC
17 magnitudes
companion being
further,
objects
can detect
fainter arcsec
to see a dim
star
than away.
the resobscured an object its bright
This
is like
in full moonlight.
REFOCOS MECHANISM HODE CONCEPTUAL
LAYOUT
OF FOC IMAGING
Another feature in the f/96 optical path is a series of four filter wheels, which contain 48 fil-
MODES
ters, Figure
3-2
Layout, FOC Relay Systems
Optical
3-3
prisms,
and
example,
if the
send
beam
the
other
optical
astronomers through
devices.
choose,
they
a magnesium-fluoride
For can
prism to emphasizethe spectrum. optical
See
Figure
far ultraviolet
coming
end of the
3-3 for the complete
ing.
f/96
This
trum
layout.
through
The f/48 Optics
System.
This system
will allow
a
wider
field of view at (44 arcsec)
2, but the reso-
lution
will be less than
f/96 optics
sys-
thus will be reserved
for
tem.
The
f/48
system
with the
spectrographic
purposes,
target
and as a secondary
searches,
To use the f/48 may need light path
system
other
duties
such
optics
the HST orbital
The
as
of the f/48
are
two filter wheels, detector.
and
a detec-
The
also has a 20-arcsec-long
spec-
troscopic rotated
slit in its aperture. into
the
optical
A special
path
diverts
High that
AND iT OPTICAL
MIRROR
the
Faint
slit has
a limited
resolution Object
many
light
The
light years,
optics
also
include
can be used either
sources
two
filter
with the main
_- PRIMARY
MIRROR FILTER
WHEELS FOLDING
MIRROR
-_
REFOCUS
SECONDARY MIRROR
SOURCE
LIGHT
PHOTOCATHODE
Figure
3-3
F/96
as a
wheels, optics
or
with the spectrographic optics for specialized viewing. The filters can, for example, block out
light
/-
THE
spec-
such
7
CALIBRATION
and
FOC
AXIS
_1_
is
falls
Spectrograph
I
INCOMING
quality
is in measuring
across
light
register specin the 2000-A
or nebula.
f/48
which
SHUTTER
6.6 arcmm
dis-
spectral
of the diffracted
Spectrograph.
value
spread
galaxy
REMOVABLE CASSEGRAIN FOR fl288 WITH APODIZING REMOVABLE
a specThe
detector.
spectral
Resolution
trograph's
mirror the
grat-
into
into the
resolution
This
between
The f/48 system
reflects
spectral
range.
the
reflecting optics, tor like the f/96
light
light
wavelengths.
2000, which means the detectors tral lines only one angstrom apart
position
system
the
composite
spectrographic
The
relay.
to be readjusted to redirect the main into the f/48 aperture. The f/48 optics
components
breaks
a diffraction
range, depending upon the spectral order chosen. It ranges from 3600 to 5400 ,_, for the first order to 1200 to 1800 ._ for the fourth order.
system is identical in overall structure to the f/96 and shares the same calibration device. The separate
grating
of the
persed
the slit onto
f/96 OPTICAL
Optical
3-4
RELAY
OF THE
Relay
System
FAINT
OBJECT
Layout
CAMERA
certain
wavelengths
length
ranges.
optics
or select
Figure
very specific
3-4
is the
photon
wave-
detailed
burst
f/48
layout.
recorded 3.1.2.2
The
Photon
Detector
System.
light
There
minutes
A,. The
science
image verted the
reconverts tron.
in three the
An
for every
an
trates
the path
stored
enter
center in
image
the
an
original
amplified
processing
is produced
detector
signal
Figure
from
of
by the
video
science
each
to the
3-5
the point
photon
processing
data
store,
depending
object
being
store upon
extremely the
exposure
The size of the completed
illus-
the
when
light
light
pixels, burst unit q_ically
size
format with
originally is a square each
is and
ly-shaped doubled.
LIGHT
a
,-_
PHOTOCATHODE
_
THE
Figure
3--4
to
observation. magnitudes
last
up
to ten
F/48
pixel
picture selected. measuring 25
by 25
depends The
upon
standard
512
by 512
micrometers
lights, and the pixel size can be This will affect the number of photons
ANO M...OR 7
_'1
up
location,
with
may
the The
(1/10,000th of an inch) in size. Other formats can be chosen for larger, smaller, or different-
-P.,MARY M,R O
"-_oRINCOMING
each
of the
objects time
upon
or record
at
the length distant
ten
observed.
will count bursts
An
between
tube,
to its processing.
location the
video
hours,
position.
by a
camera
unit.
of a photon
elec-
ten
photon
to 28, hours.
pro-
at that
in a period
of the data
depending For
is intensified
and
65,535
detector
to photons,
television-type
sends
determined
Then
photons
intensified
video
it hits the
steps. output
100,000
FOC
The
source
electron
high-sensitivity which
the target
intensifier, where the photons are conto electrons. High voltage accelerates
electrons
viding
from
light
brightness
75 to 100 microns
Every time an incoming photon the diodes at the same location, the
can be produced
are two identical detectors in the FOC. They are sensitive to radiation between 1150 and 6500 photons
is a spot roughly
in diameter. bursts onto
Optics
3-5
FI48
Relay
OPTICAL
System
RELAY
Layout
PHOSPHOR--_
PHOTOCATHODE \ \
3-STAGE INTENSIFIER INCOMING
-_
_
I1
_,
PHOTON
particularly
_ /INTERNAL _TARGET\
/ 4111 /'_.
_
_r BEAM_
IrEBSICON
_/
/_
J_/J
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_oo
11..U..US;'M ';'ZTUSE
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w,,,DOW= \ HOT-BIALKAL_r_c
READING
PHOTOCATHODE
(NSSC-I), the & Data Handling
with the
FOC's
3.1.2
RELAY
I
LENS
I
A
v_
standard
spacecraft
Scientific Instrument unit computer which,
on-board
computer
as a back-
the FOC.
Observation
Modes
I
i
I,v
NASA
computer Control
up, operates
/
__
to the
4
The
I SCIENTIFIC
I'.?;_'_L''
I DATA
Faint Object
modes:
Camera
targeting,
has four observation
imaging,
occultation,
and
spectrographic. Targeting Figure
3-5
Photon
Detection
the FOC can count because transmission limits. One
advantage
light
in the
data
any time without lected.
This
study
of the
system
store
destroying
is quite
and
the data for
being
target
cated
at
light is stored
tape
recorders
until
Telescope (STOCC) ellite
it can be sent
Operations
System
and
image
by the HST
FOC
process
cludes
transmission
Data
Relay
the FOC
final step
support,
support,
body
Sat-
omers
in the
which
dataprocessing,
and is performed
tronics system. tronic functions, keep
The
is electronic
physical
uses
in-
is the
linking
the
FOC
and to
optics
elec-
protected
communications the
Space
Then
of view.
optics
system
Various
for-
change
the
to
wavelength
units
can
range.
fingers
study
the
would within
3-6
and
one
the
a bright surrounding
a galaxy
celestial mode
uses
high-resolu-
object
be occulting
so astron-
background. a quasar
visually
to see
obscured
by
brightness. mode
f/48 aperture
to diffract
composite
wavelengths.
ranges
of
Occultation
Spectrographic
to separate
Telescope,
eclipsing
object.
cross-dispersing are command
of the
of a target.
to occult
the quasar's
in space. There
field
selected
the
by another
if it exists
and
by the FOC
and
of view.
FOC
either
are
size and/or
An example
The system also services elecsuch as the thermal control to electronics
field
to place the light onto the or spectrographic slit, lo-
image
the coronographic
Electronics.
FOC
of the
filters
Occultation
Center
(TDRSS).
FOC
the
a direct and
tion apodizer 3.1.1.3
or spectrographic
to the Space
Control
via the Tracking
mode
to take tape
within
on the edge
Imaging
intermediate
light.
on magnetic
us-
col-
mats The
any observations
coronographic
the HST is repointed coronographic finger
is that the
can be viewed
useful
developing
storage
precedes
devices. A special exposure of the target, using the FOC, is processed by the SI C&DH to find the
of the detector
science
ing the FOC's
System
of data
mode
uses
prism the
for specific
light
the
long
the incoming Filters will into
study.
slit in the light
into
and
allow
astronomers
narrow
wavelength
a
3.1.3 Faint
Object
Camera
Specifications
•
Providing various
Table
3-1
Faint Object Specifications FAINT-OBJECT
Weight Dimensions
possible
dust referred
visible
as huge clouds
ample
of these
Magnitude Range
5-28 m v
in the
Horsehead
Wavelength Range
1150-6500 Ang.
Focal ratio can be adjusted from the ground. The most be f/96.
•
The
clearly
imposed
focal
The
wavelengths
band from
1200
and
maximum
range.
concentrate
to 1800
Angstroms.
ratios
depend
Object
will For
light
upon
times
•
be
Studying
Measuring ies and
•
Examining irregular
pattern
Figure
3-6.
a
exam-
to inter-
Courtesy
observation
but
indicate
will be used,
with other
on a number
Among
relating stars •
Camera
in conjunction
tions.
dark-cloud See
on the band
(clear
and exposure limits.
struments,
is the
Nebula.
ex-
for
Figure
the
Observations
The Faint
clouds
and
A good
for
Stellar 3.1.4
matter
in the heavens.
limi-
itself. maximum
usually
may
signal-to-noise
ference) ranges FOC's
studied
the
study
Specific
to as interstellar
specmicro-
ratio.
within one
except
by the optical
of the Space Telescope of view listed are the
each
ple,
discussed
as commanded frequent use will
will be resolved
light halos
tations Fields
of
NOTES:
•
light
are
3.1.4.1 Stellar Evolution. Astronomers ulate that stars form out of the gas and scopic
slight
observations
phenomena
explorations
ESA (Domier, Matra Corp.) f/96 f/48 11,2. 22 arcsec 2
SPECIFICATION
•
resolution
System
CAMERA
3x3x7 ft (0.9x0.gx2.2 m) ED. Macchetto, Eur. Space Agny
Optical Modes Fieid of View
•
These below.
700 Ib (318 kg)
Principal Investigator Contractor
•
Camera
high Solar
of important
its priorities interstellar to the
formation
and
observa-
for evidence evolution
waves
coming
explosions,
in-
are: gas clouds
of the farthest
Astronomy
scientists
clouds from
are
believe,
and from
from
the whirling
Growing
hotter
galax-
and
supernova movement
of
This violent motion onto themselves.
and heavier,
in a nuclear
shock
newly-formed
stars,
of spiral galaxies. the gas clouds
begins by
the clouds
ingly compress into a spiraling mass around a dense core. Eventually
of
Observatories.
buffeted
nearby
the arms collapses
ignites the distance
gas
internally-combusting
by itself
HST scientific
formation, the
Optical
The Horsehead Nebula, A Dark Gas Cloud
3--6
when
National
explosion
and
increasof matter the mass
become
a
protostar.
quasars globular
clusters
and normal
and
Unfortunately,
galaxies
in
3-7
development
clear
observations
is difficult
of a protostar because
of
the
surrounding
mass
"cocoon."
When
explosions
blow
gas,
leaving
ing
gaseous
clumps, develop
of
matter,
a new star away
only
often
begins
much
scattered
called
a
igniting,
of the clumps
objects
orbiting
the
astronomers into planets.
theorize,
could
these
the
process
team
obscuring
tions
a clear
planetary
matter.
and dark
clouds
star.
background
These
eventually
Certain
stars
for planets mers have
cloud
from
months,
hold
special
with prethe camera
the FOC
Figure
3-7
may
picture
starlight. angles,
the existence a planet.
capabilities
a muddy
But,
by
rendering
of the FOC of the
taking might
images be able
See Figure
of
the
of a
Observa-
because
the FOC
any faint companions.
artist's
3.1.4.2 tent of
Measuring Distances. the universe? What
between
stars?
is an art-
interest
in the
search
to
3-8 for
photographic
Protostar
ability
What is the
is the exdistance
with its high
to detect
objects
angular light
previous calculate
observations, will help direct geometric dis-
to astronomical and parallaxes
objects. By examining for clusters of stars,
along with the speed at which material is dispersed from the stars, astronomers can accu-
System. Astronoin the motion of
3-7
The FOC,
and
years beyond astronomers tances motion
Figure
the masking
different
resolution
with preplanetary
our Solar variations
perhaps
technique.
of this
protostars
using
equipment,
of a protostar it.
that suggest
fragmentation
candidate
changes.
beyond observed
as much
view of a protostar
over
dynamic
ist's conception matter circling
from Studying
and its spectrographic capture
to observe
as possible,
to, perhaps,
using
will produce
isolate
hopes
stars object,
of condens-
an The FOC
single
companion
rately
measure
with Preplanetary
3-8
distances.
Matter
central regions mayreveal the sourceof that intense radiation. Of particular interest is the center of galaxy
NGC
(Figure
3-9).
sive object sions
4486,
object,
at its center,
An important
measurement
magnitude
astronomers the
Cepheids
of
different
measure
the
in the
Large
Globular
ety of galaxy
types
precise
distance
Magellanic in more
Clusters
and
globular
clusters,
Couflesy
to
Cloud, distant
will be used to seek which
radiate
ing galaxy with
clumps
center hension?
A
answers.
Figure
the
than
from
the
the center
tre(Fig-
massed
object
sized
high-resolution
Clus-
the
f/48
program using
broad-band
Optical
Astronomy
The Elliptical Messier 87
observation center
National
Galaxy
would
the f/96 optics
filter,
and
the
Observatories.
examine
the
system,
with a
spectrographics
of
optics.
Many quesand galaxies, instruments
The
con-
together? beyond study
The cover
masking these
filled
may
have
Is the
they
and
compreof
also
will concentrate
3-9
of the
faint
galaxies.
formed
shortly
about the early of the universe.
these
luminosity
ability
their
on known
are surrounding
den by the tremendous
surround-
centers
FOC
sars to see if there
and galaxies, the
bright
3-9
sys-
and a vari-
One question
clusters
energy
Are
of stars
a massive
clusters scientific
of some
more
itself.
Galaxies.
fill the universe.
tions arise when studying and the FOC and other cerns the centers
radiating
is a single
producing
Once
galaxy called
If the center
or pulse reguAstronomers from the rela-
The
ters of stars,
colli-
The clouds known as
Cepheids.
they can measure Cepheids tems more accurately.
3.1.4.3
by stellar
that add to the grow-
indicator
Magellanic Cloud. distance indicators
Cepheid variables, which radiate larly at two distinct magnitudes. can calculate relative distances tive
created
matter
is a mas-
"Photographing "A Secondary Body
distance
will be the Large contain standard
there
be a quasar
mendous energy ure 3 - 10).
3-8
suspect
of the galaxy.
it could
elliptical as Messier 87
known
Scientists
and collapsed
ing nucleus
Figure
also
galaxies
may
composition
FOC Since after reveal and
qua-
galaxies
hid-
of the quasar. may
help
many the
dis-
quasars
Big Bang, information
development
Figure 3.1.4.4
Examining
With
the
planets, the
FOC,
Quasar
Solar
System
astronomers
moons,
Solar
3-10
can
asteroids,
System
and
more
Hypothetically Objects.
observe
other
clearly
planets.
the
bodies than
spacecraft.
But the FOC
astronomers
to examine
a planetary
in
from
years
of the brief
time
instead
ager's
"fly-by"
tions,
moreover,
FOC
cannot
light
trajectories.
interference
place
faint
from
dictated
Planetary
can take examine
will allow object
tary moons
in greater accurate
tion,
orbits,
will
study
3.2
example, of
will advance
Martian
Mars
of the
wind
formation;
movement.
Closeups
tune,
Uranus,
and
edge
of the
surface
FOC
outer
when
the of
The
of Mars, such
storm
velocities;
seasonal
polar-cap
Saturn,
will expand
composition
Faint
and satellites
will allow
asteroids
detail
than
and plane-
ever The
using
before
axis
composition. its
to
orienta-
FOC
also
spectrographic
device,
and
a variety
Spectrograph
High
Resolution
are
Each
FOS
3-10
faint
but
objects
the FOS
while
in much
they
overlap
up each
detecting
the
greater
to different
is a medium-resolution faint
The
objects,
light
to back
and
Spectrograph
sensitive
spectrum,
For objects
the range resolution
of these
brighter
of the
(FOS)
instruments.
very
is most
in mid-range
range.
that the
from
tions
captures
dynamics
companion
what The
Nep-
SPECTROGRAPH
Object
studies
detail. as
OBJECT
light
GHRS
our knowl-
and it is possible
additional
for
understanding
of Jupiter,
and
Goddard
or moon.
weather,
dust and
Pluto
planets,
may discover
and and
white-cloud
on these
scientific
geography patterns
surface
resolution
dimensions,
comets
FAINT
studies observation
angular
of the smaller
determine
(GHRS) Direct
FOC
by Voy-
because
the sun, earth,
The
87
optics, the coronographic of filters.
for
observa-
even
objects
In Messier
examination
ground-based observatories. Scientists will obtain data similar in detail to that obtained from the Voyager
Centered
porsome-
other.
instrument. a broad
with apparent
22 and 26my, the FOS of 250. This means
It
spectral
magnitudes
in
has a spectral that in the
1500-Angstrom tral
lines
range
as close
brighter
objects
1300,
it can differentiate
as six Angstroms the
separating
resolution
spectral
to 8000 duce
A,
very
objects,
in the broad
velocity
the
of celestial and
mer
can help
hot,
X-ray-emitting
stellar
discover
dust
passing
also
intensity
the
internal
clouds,
through
The
has
The
aperture,
The FOS
acquisition. various
for
Four
optical
axis.
Research
Corp.,
Marietta
the
one
through cillate
are
light
the
was
paths
leadership
built
travels
a prismatic degrees
of
light
of Applied
mirror,
goes
which
from
the
through
an
and
--
all light
longer
than
6800
The
The
(blue)
See
detector
wavelengths.
of the optics;
communication
support
ics equipment.
pass through can rotate plane
so
passes
for the
optical
Figure
3-11.
electron-
systems; and
the
onto
beam
optical
axis.
wheel.
22 The
order-blocking
waves
short
structural
os-
filter This filter
passes light in the desired spectral range. For example, if that range is 4500 - 6800 A,, the fil-
objects
Digicon
reflects HST
on the filter/grating
back
consist
if they
the analyzer
light
waves
aperture
off a collimating
and
the
Light
the selected
beam
components
send
through
flects
power,
shield.
in increments
for
ics,
as galax-
for spectropo-
in a certain
and for
FOS
such
are selected
away
mounted
by Martin
in the instrument
to a red-sensitive
emitting
sky One
planes
longer (red) wavelengths, a blue-sensitive detector
leads
targets,
plane
sources emitting the other leads
one
and
of view.
to act as a light
analyzer.
and
a a qua-
target
specialized
polarized The
the
apertures
field,
are
occulting
surrounding
fields
for wide is blank
in a particular
Light
Corp.
are two optical
observe
is
apertures Two
surrounding
different
These
a magnetic
in diameter,
light
a galaxy
a polarization
ter blocks There
faint
apertures
larimetry.
infor-
to the HST
President
FOS
of
of 12 apertures.
The smaller
(e.g.,
serves
Three
X-rays.
the light
parallel
under Vice
one
down
of 22 degrees.
680 lb (309 kg), and now
Pointing
light
observations.
with
ies, while
3 x 3 x 7 ft (0.9 x 0.9 x 2.2
Designed
operating.
into one
apertures
aperture
for-
Description
m) and
R. J. Harms,
sys-
a filter/
detectors.
4.3 arcsec
capture target
background
of inter-
can polarize
largest
used
only
is rectangular,
and
for target
sar).
them.
Physical
begins
the incoming
paths
through. 3.2.1
optical
mirrors,
port leading to the aperaperture port remains
the FOS
two optical
bright
cooler
reveal
processes
which
FOS
and the separate
places
apertures
between
by the
observations
about
of
and
and their
bombarded
until
the HST
(wavelength
stars
The
apertures,
is an entrance assembly. The
closed
the
FOS
capabilities.
binary
Spectropolarimetric stellar
nature
the interactions
companions
mation
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of light)
wheel,
There ture
the
measure
spectropolarimetric
polarization
a
will pro-
includes
chemical
(wavelength
and
grating
System.
special
components
will help
targets.
spectrophotometric of light)
range
the
FOS
to
of targeted
of the chemical
to studying
objects,
This
portraits
this spectral
of most
In addition faint
infrared.
Optical
tem contains
as 1.2
the FOS can display A, in the ultraviolet,
chemical
because
emissions of stars.
near
as close
3.2.1.1
For
increases
lines
Angstroms. In both cases, spectral range from 1100
spec-
apart.
shorter
A.
The
filter/grating
wheel
4500
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light
re-
sends
the
filtered
mirror,
to the grating
than which
wheel. is a carrousel
which
contains a variety of gratings. Six gratings the range 1150 to 9000 _, with moderate
and
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four
diodes,
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to 8000
electron
observation at least
the
1700
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a "pulse"
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aiming.
the
Components
and amplifies
but with lim-
of 100. A clear
an undispersed
3.2.1.2 wheel
3500
3-11
then
analog
all
for final
central
electronics
remote
communi-
and above
from processor
it is sent
Communications.
the
the
for shaping
to the central
processing
optics
detector
bench diodes into
electronics
and transmission.
The
central
electronics
microprocessors for each the
assembly
and
detector.
support
The
filter/grating
electronics,
small
wheel
contains
the
diode
pulse-counting
hours.
desired
setting,
and
mechanism.
one rotate
to the
array,
observation
computers
based on preset STOCC commands, the magnetic focus system to direct toward
two
Then
the
The
central
from
50 microseconds
cified
FOS
"on"
period,
the
data
added
together
Time-tagged
and
Systems
In addition engineering ages,
and
cessors.
to science data, the FOS produces data, such as temperatures, voltprocessing
All data
rectly
Module.
are
data
from
stored
on
the
study
micropro-
tape
or sent
Operational
clock
coming
data
up to every
and
of the
The
spectroscopic
operation
will be the
stan-
dard
way to collect
data.
astronomer
mak-
a grating
for the
and a prisms.
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See
Faint Object Specifications
3-2
can
Section
the effects.
analyzer
be measured
3.2.4.4
for
Spectrograph
Faint Object Specifications
Weight Dimensions Principal Investigator Conl_actoR
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polarization
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correct
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Modes
The
out
are used for objects at reliable periods,
takes
with
points
required.
read
to four
to 100 seconds.
operations,
The FOS has four modes for collecting science data. They are spectroscopic, time-resolved,
tion
minutes
are
for a number
objects
spacecraft
to the ground.
3.2.2
detector
time-tagged
di-
data
operations that pulses
electronics assembly sends data, through the communications unit, to the SI C&DH unit in Support
several
communications
Time-resolved with radiation
the
from
resulting
HST or ground intervals.
operate electrons
control
time,
Path, FOS
3-13
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Magnitude Range Wavelength Range
19-26 rnv
250; 1300 1100-8000 Ang.
one
3.2.4
Observations
The
FOS will observe
many
of the objects
being
targeted by other Sis, but for different information. Three observation plans being considered would study galaxy formation, can be used to test distance composition
and
3.2.4.1
Explosive
theorize
that
ies, and
of interstellar
Galaxies.
quasars,
the Milky
stages
quasars
Seyferts
searching
Astronomical
exploding
development.
recedes
from
galax-
The
as
FOS
galaxies
will
like the
for relationships.
repeatedly expand
Seyfert
may be related
and exploding
data
which
dust.
Astronomers
Way galaxy
in galactic
examine
they
origin
how supernovae formulas, and the
from
expel
quasars
indicate
nebulous
rapidly
as
the
us at speeds
that
clouds
of gas,
entire
quasar
approaching
light. Extremely distant quasars are billion light years away. Astronomers
that
of
nearly 14 believe
these distant quasars may have existed since the earliest formative stages of the universe. If so, nebulous could
matter
surrounding
be the beginning
Exploding
galaxies,
the
center.
are expanding
the
nebulous
elliptical core.
jets
exploding
and
vast,
hot
of a quasar. galaxy,
of
M87,
matter
3-13
clouds
much
like
At least
one
may also have
spewing
shows
giant
to quaoff from gas
at high velocities,
exploding Figure
development.
as Seyferts
emit
clouds
quasar-like
quasars
bear a resemblance of nebulosity thrown
Seyferts
that
of galactic such
elliptical galaxies, sars in the pattern
these
two
from
the
examples
of
galaxies. Courtesy
The
FOS
sources,
team
and
for chemical late these
the and
earlier
its whirling,
left),
and
study
clouds
physical galaxies
nebulous
tistic comparison quasar (top left), (lower
will gas
these they
energetic
eject,
relationships
Figure
that
Figure
Milky
3.2.4.2 vae
3-14 is an ar-
Way (lower
Astronomy
Observatories.
reSupernovae
are
sive Once
right).
3-14
and
dramatic
evidence
active.
A supernova
violently
of the four types of galaxies: Seyfert (top right), elliptical the
Optical
Two Examples of Exploding Galaxies
looking
to the Milky Way, with
arms.
3-13
National
gasp the
of a dying
star
supernova
erupts,
Distance. that
the
is the such
Supernouniverse last,
as a red
most
of the
is
explogiant. star's
Figure
remaining leaving
matter behind
a dwarf
ever, don't know va explosion.
With
the FOS
can examine practically thereafter. magnitude, magnitude
scatters
3-14
into
star.
the exact
the
heavens,
Astronomers, details
x.__.
Galaxy
3.2.4.3
supernovae as the nova Luminosity to calculate
to measure occurs and determines the
for
A planetary
su-
de-
FOS
will
will provide different
3-15
producing
distant
eons
that
and mass
anal-
planetary
in the history
a subject yield
the
of stellar
of
3-15.
will
nearby nebulae This particular
a portrait
shell
Figure
with
light
chemical,
material study
See
astronomers
temperature,
of the
faint as 22my, and Magellanic Cloud.
magnitude measurement Law to better estimate the constant H. A conclusive
star.
of ultraviolet
yses
It grows the star's
as an expanding
the dying
provides
studies
accurate
termined by the against the Hubble value of the Hubble
supernovae
of Stars.
into space
A nebula
apparent
the distance
Evolution
gas encircling
periodically absolute to the
The
atmosphere
luminosity
with
distance
can then compare
the study of many Space Telescope.
nebula is a remnant of a supernova. large and cool until stellar forces blow
astronomers
is compared
Types
answer requires with the Hubble
how-
pernova.
Astronomers
of Four
of a superno-
spectrophotometer,
which
Comparison
light.
The
nebulae
as
in the Large comparison evolution
of the
universe.
from
Goddard
High
(GHRS). Center,
Spectrograph
Developed by Goddard Space Flight under the direction of J. C. Brandt, it
was built
by Ball Aerospace
Ultraviolet sphere
Resolution
rays rarely
but have
servatories
pierce
been
most
Ultraviolet
The
GHRS
than
the
is more
IUE,
the
examined
in space,
national
Systems. earth's
before
recently
by the
Explorer
(IUE)
sensitive
to faint
to 17my,
though
atmofrom
not
ob-
Inter-
satellite. objects
as sensitive
as the FOS. Much more importantly, the GHRS is far more accurate and has greater spectral resolution than the IUE. Palomar
Figure 3.2.4.4 ter. One
3-15
ally attached is the dust. particles
material
3.3.1
Nebula
scopes.
invisible
Astronomers in great
--
The
FOS
clouds,
netization. mation
for
of the
dust
hope
findings
about
fil-
much density
about
clues
passing
small
and
its mag-
these
studies
the
far fainter
star
hand,
mation
ment
designed
the
objects universe.
for ultraviolet
objects
The
differ
in and
in sensi-
GHRS
differences
objects,
down
can
between
resolution
of
to 26my.
Physical
scientific
compositional in spectral
infor-
detail.
Description
also
is aligned
axis. Sized
parallel
produces
will tell
closed
spectra,
systems, systems.
GHRS
support
and a structure The
computer
to the
HST
at 3 x 3 x 7 ft (0.9 × 0.9 x 2.2 m)
and 700 lb (318 kg), it contains
SI C&DH
an optical
system
electronic housing unit
and the en-
handles
the
functions.
and The
the vast gas clouds observation
will produce
unprecedented
3.3.2
Telescope
temperature,
and
separate
for-
that
Space
up
func-
gas clouds
The
to a spectral
other
to the
RESOLU-
from
the Hubble
the composition,
of stellar
throughout
radiation
using
they
resolution.
lines,
The GHRS
(UV)
astronomers
because
spectral extremely
thermal Ultraviolet
and
spectral
tects
polar-
process. THE GODDARD HIGH TION SPECTROGRAPH
in some
But they also serve
resolve
optical 3.3
stars
Spectro-
For a broad spectrum and a variety of star distances, the FOS stands out. The GHRS, on the
light
looking
overlap
as measuring
functions
and
Object
100,000, but only for objects 13my and brighter. The FOS is more limited in resolution but de-
magnetism.
Astronomers abundant
light
such
ultraviolet.
tivity
with Faint
spectrographs
valuable
the dust col-
becomes
ultraviolet
composition
produce
the
tele-
because
clouds
of strong measure
dust
chemical
fields
the dust
can
that
two
tions,
not gravitation-
ground-based
theorize
evidence
through
to
magnetic
through
ized
in space
Comparison graph
The
to a star -- that remains unstudied The reason for this is that the dust are
tering
Photograph.
The Composition of Interstellar Matelement of the interstellar medium --
the cloud-like
lects
A Planetary
Observatory
optical
rotating
instru-
carrousel
wavelengths,
is the
3-16
system
contains with gratings
mirrors
to place
two
apertures,
to separate the
light
a the
into
a
specific detector, and two Digicon light detectors, one for 1050 to 1700 A, the other for 1150 to 3200 ture
A,. See Figure
and
optical
3-16 for the GHRS
The
large
science
aperture
is used
to locate
the
target, observe galaxies, and perform spectrophotometric and spectrographic observations
struc-
system.
when
precise
spectral
The
small
light
of single
resolution
science
is not required.
aperture
objects,
captures
the
such as a star, and
full
is used
to obtain the GHRS maximum specified resolution of 100,000. This means that in the 2000/_ range
the
GHRS
separated
_y
CAMERA MIRRORS CONCAVE
DETECTOR
small
aperture
large
aperture.
Two
slits
_
CONCAVE
wavelength
_(__._
CROSSDISPERSER GRATINGS
the
ENTRANCE APERTURE
1
in the
needs
instrument
slits,
and
starlight
blocks
the
provide
accurately
starlight,
UV
light
the
They
are
the
be meaare
called
compared
with
very accurate
wavelength
PARABOLOID
turn, will provide the composition
a crucial step in calculating of stars and the speed with
which
toward
they
move
These
UV
COLLIMATOR OFF-AXIS
2
readings.
can
wavelengths
to produce
Lamps
through
wavelengths
These
standards.
incoming
DIGICON
these
the
for comparison.
shine
precisely.
When
area
incoming
standards
features
a shutter
To measure
of
in the
spectral
angstrom.
aperture
calibrations.
calibration
/s
GHRS
wavelength
sured
f
of an
is operating,
GHRS two
DIGICON
will display
by 0.02
measurements,
or away
from
in
us.
SHUTTER FOR LARGE SLIT INC( LIGHT
"GRATING MIRROR
The incoming light reflects mirror that directs the beam
AND CAMERA CAROUSEL
TRANCE SLITS
Figure
3-16
GHRS Optical
Structure System
and
3.3.2.2
Carrousel.
wheel
with
seven
acquisition
Apertures.
tures, arcsec ence
a large across aperture
the FOV. The
The
science its field that
GHRS
two
0.25
arcsec
through
ture
the divergent
points
is astigmatic. of the light,
at right
angles
To adjust each so the
2.0 sci-
0.03
aperture incoming
each
and
coarse
and
and
select motor fine
three
specific rotate
the
positioning
The
carrousel
to position
See
Figure
The
carrousel
can
move
the right grating
in either or mirror.
3-17.
aperfocal
has two slits set lights
arcsec.
direction
across
are not on the HST op-
tical axis, so the light coming
to
steps, to direct a desired wavelength to a detector. The carrousel motion is accurate to within
aper-
aperture measuring of view, and a small
measures
apertures
has
through
is a rotating
gratings
used
An encoder
carrousel,
a collimating the carrousel.
carrousel
diffraction
mirrors,
wavelengths.
3.3.2.1
The
off onto
tings,
merge
ject.
again.
used Two
diffraction.
3-17
has
to lock settings The
three
mirrors,
the HRS reflect other
onto faint
with four
set-
the desired
ob-
objects
two settings
allow
with
no
bright
tion
increases,
electron
the
count
intensity
drops.
spectral
resolution
studied record.
longer
decreases
This means a celestial
to
collect
and
the
that at higher object
enough
must
be
energy
to
GRATING
The
spectral
frames
G;; G
resolution
depicted
20,000
(middle)
sample
from
2000
to 100,000
ber of spectral between 1475 cally
of the
ranges
spectral (top)
(bottom).
The
to
num-
features measured in the range and 1480 A, increases dramati-
as the wavelength
range
shortens.
G 270M ACQUISITION
The
MIRROR
grating
carrousel
sends
mirrors, Figure
3-17
GHRS
Carrousel
up to -1my,
to be targeted.
which
The
latter
the
incoming
light
for analysis. observe
carrousel into
GHRS
the UV (20,000),
lution.
The
highest
tained
with
two
or high
overall
spectrum
example, Grating range just 29 A displays details
Figure
in one
cave
gratings,
along
the
the detection
band
frame
the
by each
tradeoff
cross-dispersing Table
per second
For
Table
3-3
MODE
3-3
MEDIUM RESOLUTION G140M G160M
grating.
between
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Two
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Diffracted
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wavelengths
the cast
gratings
place
each
light order
GHRS Grating Spectral and Spectral Resolutions
range. The more the more intense
electrons counted the source for that
wavelength
band.
as spectral
WAVELENGTH
SPECTRAL
RANGE
ORDER(S)
SPECTRAL RESOLUTION
(x io4')
Ranges
WAVELENGTH AMOUNT COVERED IN ONE FRAME
1100-1700 1t50-2100
1 1
1.8-3.0 1.5-3.0
27-29 33-36
G200M
1600-2300
1
G270M
2200-3200
1
1.IF2.7 2.1-3.3
38-41 45-49
RESOLUTION G140L
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1
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290-291
HIGH RESOLUTION ECHELLE A ECHELLE B
1100-t700 1700-3200
53-33 3,3-18
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LOW
for a particular
wavelength per second,
However,
onto
of the
and brightness. Brightness is number of electrons striking
diodes
light
light
fea-
decreases.
290 A wide.
covered
illustrates
spectral resolution measured by the
the portion
called
highly
gratings.
G140M displays a spectral wide, while Grating G140L
spectrum
3-18
the
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targeting
camera
grating
Since the echelles reflect lower orders only, it is important to keep the orders separate. So the
is ob-
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concave
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reso-
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to me-
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on the
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wavelengths
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increases,
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out
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echelle
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spectral
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light
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3.3.2.3
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0 1474
1476
1478
1480
the
1482
the
window
of the
inward.
The
in the
diode
array.
magnetic Each
Digicon electrons
field
diode
and
and
counts
are
land the
on
elec-
WAVELENGTH
trons the Figure
3-18
Data From Three Grating Settings
hitting amplifier,
relayed
so on.
compensate
Then
scientists want.
cross-dispersal
can
Figure
examine 3-19
any
illustrates
light
Detectors.
tors are photocathode tons in the incoming wavelength
tive:
,'_ for Digicon
tube
contains
The
Digicon
range
to which
1; 2000
mation
pulses.
exposure
to
device
This information or after time.
system
can
re-align
for
the
motion
data
The
build
magnetic
shifted of
is
data
the
to
Space
the GHRS
detectors
go to the accu-
in SI C&DH
memory.
Then
passes
through
the SI C&DH
the inforformatter
and to the ground for analysis. If no communication with the STOCC is available, data are
it is sensi-
stored in recorders.
,'_ for Digicon
a photo-sensitive
from
mulators
detec-
tubes that count the pholight. Each Digicon has a
maximum 2. Each
goes
technique.
Digicon
1400
signal
Telescope.
the
Data 3.3.2.4
The
to an accumulating
immediately
a preset
deflection
event.
all diode
either
on parallel horizontal bands -- all first orders on one band, all second orders on another, and they
then
that records up over
order
it as one
window,
3-19
the
HST
on-board
science
tape
SIGNAL BOOST PREAMPLIFIER
INTERFACE WIRING _DtODE ARRAY DIGICON DIGICON WINDOW INCOMING
Figure
3.3.2.5
GHRS
tion control resides
Software.
software Control
and
The
GHRS
programs
for operational
Observation
time
Targeting
for the upcoming
• •
The
science
seven
selects
rotates and
sets
collection
--
make
the
HST
and
requests
field,
collects
that
exceed
servations
compensates
high-resolution of incoming
the
diode
data,
ob-
The
and checks
motion
for
the quality
data.
3-20
uses
onto
the
the
large
target
and
to repoint
target
into
light
targeting
relative
to a brighter in the
HST
maneuvers,
observer
also
target
acquisition
image
of
the
Planetary
Camera
aperture
to find
centers
object.
Then
aperture
the brighter
acquisition
for specific
small
measures
smaller
using
Different
and
the
the
procedure
aperture
is centered
as a guide.
under/overexposure
for vehicular lights,
stops
mode
adjustments
the
in the large
selected
and
place
The basic
small
has two baacquisition
necessary
the target target
detector
This to lock
aperture. location
target
acquisition.
aperture
ex-
a tar-
Spectrograph
modes:
Acquisition.
the
system.
controls
Modes
Resolution
data
science
observation. pinpoints
maneuver
control
High
sic operational
-- maps the field of view and sends to the STOCC if commanded.
magnetic limits,
pointing
SSM pointing
Mapping the data Data
for and
Operational
Target
setting,
Detector
but
unit (SI
includes
and aperture,
-- searches
get by sending to the
Handling
Digicon
3.3.3
phases:
to the correct
posure •
observa-
-- on command,
detector
carrousel
Data
GHRS
in the Scientific
software
set-up
the GHRS
The
GHRS
computer
C&DH).
•
3-20
is not in the unit itself,
in the NSSC-I
Instrument
The
LIGHT
its the by
object
mirrors
are
targets. can use two variations mode.
target
with
before the
One
first
takes
an
Wide
Field/
using the large
GHRS
target.
the
of the
Having
the
large
WF/PC
image
helps
the GHRS
target,
such as one
surrounded
similar
brightness,
which
on-board
The
target
other
GHRS
or precision
important,
the
Examples
would
than
knows centering
GHRS
can
of the target
is less
be pointed
be a repeat
object
will do.
Data
Acquisition.
lation
data
and
Accumulation
are
using
rapid
two
is the
seconds, can
minutes,
react
blocking and
Rapid
the target,
hours,
17-11 rr_
Wavelengttl Range
1050-3200 Ang.
time,
data
generally
After
each
Observations
The
GHRS
will
prove
celestial
mode.
•
Star
•
Studies
and
the
formations
as
3.3.5.1
software
and
of quasars
of
and dispersion medium
binaries and
the
other
extragalactic
has past.
a very
between time period
recorders, SI C&DH
Composition
and
Dis-
persion. The chemical composition of the atmosphere of stars, and of the surrounding matter,
earth
the observation
for
Atmospheric
short
is a question
long
GHRS
provide
may
data for atmospheric elements
in the patterns
by astronomers.
answers
cal
wavelength the GHRS.
50 msec
debated
tral
by studying
composition.
atmosphere
The specChemi-
have
unique
that can be identified
using
the indi-
cooling
the
a number
objects
can be stored
in on-board
in examining
radiation
objects:
information. this mode,
One
bypasses
useful
of ultraviolet
method
vidual block of data goes directly to the ground for analysis as the next time period begins. Data formation
resolution
Atmospheric composition Content of the interstellar
the interruption
provides
13 seconds.
2(X)O-100,000
for consistent Time can be
such
by pausing
it after
readout
observation and
or
to interruptions,
resuming
Resolution Magnitude Range
• • normal
observations interruptions.
to
accumu-
(direct)
used for gathering GHRS spectral The GHRS software accommodates lengthy sudden
ways
the GHRS:
readout
of data
monitoring quality and
2 arcsac 2 target, 0.25 arcsec 2 science
3.3.5
science mode
Apertures
with
target calibrations, or studying extended like galaxies, where any segment of the
acquire
J.C. Brandt, NASA]GSFC BallAerospace
blindly.
observation,
known objects
There
SPECTROGRAPH
Principal Investigator Contractor
a WF/PC
of the
HIGH-RESOLUTION
700 Ib (318 kg) 3x3x7 ft (0.gxO.9x2.2 m)
acquisi-
the location
Goddard High Resolution Spectrograph Specifications
Weight Dimensions
to map
This
3-4
GODDARD
the
less sky.
if the observer
target,
uses
aperture
2 field.
Spectrograph
confuse
variation
less time to process
but it covers
Goddard High Resolution Specifications
Table
the sky, up to a (10 arcsec)
Finally,
could
3.3.4
of
searches.
field of view of the large
image,
a difficult
by neighbors
target-acquisition
tion aid takes
locate
but the incomputer.
from
3-21
such red Zeta's
study giant
may star.
atmosphere
focus
on Zeta
Material
Aurigae,
is being
to an unseen
pulled
compan-
a
ion astronomers
believe
star.
will study
The
phere
GHRS
to analyze
may
be a younger,
the escaping
hot
3.3.5.3
atmos-
Star
ing binary
its chemistry.
GHRS. panion.
example
Io, orbiting canic
closer
to home,
the giant planet
eruptions
that,
Jupiter,
by
earth
they expel material Io's surface. The
breaks
and
apart
in Jupiter's
tating
magnetic
ring around ing
Io's
called
field
own
of gas,
elements, also
ring. with
This
examine
GHRS. the
volcanic
3.3.5.2 The
Content GHRS
determine
arms in spiral
can
the
study
high-pressure
Only
of high-resolution
from
For example,
Using
extended
periods,
arms
areas,
indicated
the
looking
with certain
sorption
lines,
chemical
makeup
of the absorption tures
of the
3-22 for lines.
of the galaxy in the spectrum
arms. with
dark
companion.
The
the
are among
than
their
on current
lates
that a quasar
clues
there
are
tion
and
Observa-
the most violent
spewing
out
enti-
energy
far
estimated
mass
can produce,
knowledge.
One
theory
center
massive
and
is a gigantic
specu-
black
hole
clusters, and matter nears
collisions
the
of a quasar
by
together
Extragalactic
universe,
explosions,
density
and of
gas the
nuclear
this
stellar
the extraordinary outpour3-24 is a dramatized depic-
center.
Some
quasars study
are close
ab-
can
the
quasar
center.
width
GHRS
can determine
tempera-
See
rendi-
observations
the
and
based
hole,
by the
called
arms.
to
wave-
calculate
lines will reveal
elements
a sample
absorbed
can
by a thick Epsilon
is an artistic
that is pulling stars, globular clouds into its vortex. As the
the spiral-
spectra,
astronomers
GHRS
piece
crunching produces ing of energy. Figure
spectra
of light
in the
greater
pressure,
ing gas will produce
the missing
the
intensity
through
because
the
may
Quasars
ties
for telltale
by the
hidden
possibilities.
Quasars
tions.
to
spectral
passing
missing
years GHRS
3.3.5.4
to be waves
the highest
spiral
gas. By analyzing
look
clouds
starlight
lengths
the
Medium.
interstellar
3-23
or a black
Io
would
Interstellar
the
can
is an art-
of the spectral lines (the greater the the more intense the spectral line).
In addition,
in birth,
of these
are thought
gases. over
through?
identify
galaxies
resolution
of dust and gas that still allows
tion of one
composition.
of compressed
or a protostar
shine
ring
of stars,
cloud
can
torus
not have
hole,
instrument
they
by its com-
could
Is it a pair
Figure
Epsichange
though
invisible be
two
as Epsilon or astronit. Is it translucent? A
and
3-21
eclipses. never
companion
composition have seen
spectra expelled
examine
their
is
stellar
is blocked
oxygen
Figure
of the
can
The dark
every
of almost
lines
of
com-
Epsilon
the eclipse,
light
and
gases the
or after star's
sodium, The
action.
ist's concept of what like if it were visible.
hot,
during, if the
ring of asteroids?
material
This extremely
the
a
most
spectral
same spectral omers would
to and surround-
orbiting
sulphur,
into
eclipses duration
should
star
has an invisible
companion
before,
for the
a yellow-white
also
than
Eclips-
targets
for an unusual
Aurigae's
panion.
ro-
Aurigae,
far longer
Ion
by par-
this material
ultraviolet
by
through
pulls
years,
are
Jupiter's
-- parallel
orbit.
has
observed
electrically
This
and Binaries. intriguing
magnitude,
27 years,
as far as 200 material then
magnetosphere.
Jupiter
a torus
ring
is charged
of
still has volstandards,
monumental: miles from ticles
the moon
offer
Epsilon
the third In another
Formation
stars
ejected
Figure
tion
absorption
the
from is likely
scientific
From the
to be
that
spectral
regular at what
quasar
instruments
ter simultaneously.
3-22
enough
ultraviolet
at the
observations,
the
velocity
center.
matter
This
in conjunction studying
the GHRS lines
the
is
observa-
with
other
quasar
cen-
Figure
3-21
Io's
Hot
SPECTRAL READING FOR OCCULTED LIGHT
Torus Ring
sures
ABSORPTION LINES
the
intensity
variation as short
I
and
light
from
HSP
opportunities
ultraviolet
•
Precisely
•
Test
I
of light,
to infrared.
and
any
measure
theories
This gives
the
to: the
about
for surrounding •
color
in that intensity observed over periods as 10 microseconds. It can measure
disks
Search
forvisible
mostly
by the
brightness
black
holes
by looking
of gas
pulsars, radio
of stars
until now observed
waves
emitted.
HIGHER TEMPERA'[ URE
3.4.1 Figure
3-22
Spectrum Absorption
with Liras
Physical
The High other
3.4
HIGH
SPEED
PHOTOMETER
The High tioned
Speed
parallel
Photometer to the
HST
(HSP), optical
rather HSE
also posiaxis,
mea-
3-23
Photometer,
instruments,
chanical ter,
Speed
Description
for
design example, than
is relatively and
compared
to the
simple
in me-
has no moving
is chosen
by moving
a filter
parts.
by moving wheel
A filthe
within
ST the
Figure The HSP
is the same
3-23
Epsilon
size as the other
Aurigae
(right) and Mystery
axial Sis, 3
Incoming
× 3 x 7 ft (0.9 × 0.9 x 2.2 m), but it weighs only 600 lb (273 kg). Its main structure is a box beam run-
through
ning
sembly
the length
of the
tronics, thermal, tems are mounted the
instrument
system,
instrument.
and communication on bulkheads. The is
the
optical
located
in the
forward
See
Figure
3-25
structure.
Power,
subsysheart of
detector end for
of the the
starlight
plate
isolate
coming
light.
sub-
portion
of
HSP
apertures,
overall
the
The the
aperture
ground
spectral
cal
Optical
detector
holes
Detector
system
in the forward
of four
filter/aperture
Subsystem.
consists bulkhead,
in-
directs
a
light; the medium
of
three
in diameter.
one
The
aperture
of the
back-
is most
accu-
is for locating
a tar-
The opti-
of four
entrance
directly
assemblies.
in the
much
rate; and the large aperture get (see Figure 3-27). 3.4.1.1
ranges
through
removes
as-
filters,
assembly
0.4, 1.0, or 10 arcsec
smallest
Each
13 colored
selected
beam
passes
and falls onto
assembly.
contains
certain
target
holes
filter/aperture
filter
which
configuration.
from
one of the entrance
a particular
elec-
Companion
The
in front
Four
light
assembly
light
which
passes and
through
reflects
sharpen
a
off the
the light. Then
filter/aperture
ellipsoid
mirrors,
the light enters
an
dissectors, one photomultiplier detector, and three off-axis ellipsoid relay mirrors complete
image dissector tube (IDT). Two IDTs are sensitive to light from 1600 A, to 6500 A, (ultraviolet
the optics.
through
optical
See Figure
3-26 for the layout
of the
system.
ultraviolet
3-24
visible),
and
wavelengths
two
are
from
sensitive 1200
to only
-- 3000/_.
Figure
Electrons
emitted
focused
3-24
which
Collisions
by the IDT photocathode
by a magnetic
the 12-stage
Stellar
field
amplifies
the
sky background,
section
electron
The
to
violet
filters
(3M
Polacoat),
ble
and
light
red-sensitive
measures to 7500
photomultiplier
a clear
frared
light
into the
light dissector same
The
object
HSP
ments.
tube.
PMT
tube
light
splitter
and
UV
to a certain
diverts light
light from
polarimetric electric plane).
the
3.4.1.2
an
tion
the
dissector. not
as magnetic
field
enters
from
turbulence dims
General
be
the
accessi-
fields
and
dust.
Space
should
ground
(which
be
because
causes
stars
to
is eliminated.
Operation.
involves
how many measured
HSP
the
starlight) liSP
HSP
positioning the measurements.
The
opera-
an
object,
selecting
bands of wavelengths and for how long, and Telescope
to take
those
of Once
vibrations
Light
with
than
and
of the
deciding should
measureintensity
greater
"twinkle"
in-
into
accuracy
atmospheric
simultaneously.
measures
(whose
much
(PMT)
range, close light passes
Red and blue
can make
Polarimetry
confined
a beam
can be studied
also
polarized are
filter,
material
image
interstellar
ultra-
can be measured.
light in the near infrared ,_. After the incoming
through
an
phenomena
such
through
of four
polarized
onto
can study
reflected
one
with
then
to photometry,
righO
through
overlaid
Photometric A
(lower
assembly
Polarimetry
mag-
IDT amplify electrons of the photocathode. The
for example,
Center
filter
of the IDT,
signal.
Quasar
are
into the entrance
photomultiplier
netic field lets the emitted from any area
Above
a
load
3-25
the astronomer Operations
selects Control
an object, Center
the Pay(POCC)
HIGH SPEED PHOTOMETER - ELECTRONICS
BOXES
DETECTOR ELECTRONICS SYSTEM CONTROLLER POWER CONVERTER REMOTE INTERFACE EXPANDER UNIT SIGNAL DISTRIBUTION
REGISTRATION
ASSEMBLIES
AND DISTRIBUTION UNITS
UNIT
f
SUBSYSTEM
ELECTRONICS
BASEPLATE
FITTING 'C' -_
TERIOR
BULKHEADS
REGISTRATION _,_ Fn'TING 'A' --4"I"-
LIGHT ENTRANCE
IMAGE DISSECTOR PHOTOMULTIPLIER PREAMPLIFIERS
HOLES J
TUBES TUBE
HIGH VOLTAGE POWER SUPPLIES OFF-AXIS ELLIPSOIDAL MIRRORS FILTER/APERTURE TUBES
Figure
3-25
Overall
HSP
Configuration
IDT-POLA RIMET RY ST oPTICAL
AXIS
- -- ---"-'1"--"_--
---
-- --
_/_ _3-'2"_ -_',_- - -_ - -__-_ _-_:;.z__-.._-'_Z_ ,NOOM,,_G-----_7,..,__--.'-.... __\----T "W__--t.T--_ __.,.4 ---OFF-AX,S PHoTONs /
.....
_
_, _
ENCLOSURE
_/"
y
k,_} _X'-
_'-
3-26
-
3 IDTs- PHO FOMERY
PMT-OCCULTATIONS
ELLIPSOIDS
ments "__
_
'"'"-"_/
/RECEPTACLE
cove./
light passes
through
into
the
dissector,
image
and
system,
LIGHT INCOMIN_G
•
0
*
•
o
-_o.,,9
0
•
0
•
•
o
•
0
•
0
•
•
O
•
O
0
•
0
•
•
O
•
O
•
O
•
O
10 SEC APERTURE
to the ground for later
number
each
exposure,
rate
APERTURE
which
and
amplifies
the
electronic
data
SI C&DH
or stores
depend
sends
the information
and
upon
example,
the
a very
length
of
brightness star
exposure
while
an hour
the
a bright
a one-second
measurement,
require
back-
transmission.
For
only
The
of exposures,
target.
and
HST.
the filter/aperture
to the SI C&DH.
The
star the
it, via the HSP
on tape
need
-,,,,_ o ":-'04,_E(_
passes
the data
the
o
0
0
primary moving
The
cove. _
example,
sky) without
signal
APE,TU,Ep,ATE liL__g _//._,_ __
FILTERS (IN 2
(for
ground
,TUBE
of might
for an accufaint
star
might
exposure.
COLUMNS)
0
O
•
3.4.2
Operational
Modes
•
The
High
Speed
Photometer
has
several
10 SEC APERTURE
Figure
places
3-27
the
C&DH
Filter/Aperture Tube, Exploded Configuration
software
computer
usually
when
until
the HST
general direction observation. Then mands and uses to find and lock the
commands the
into
the
Targeting depending
uses upon
make
SI
time,
mers
can
use
after another reads the com-
point
the
target,
onto
software stars.
the pointing control subsystem onto the guide stars, then onto
Once
target. light passes
through
so that the HSP of movement
can center needed
first filter/aperture the
NSSC-I.
pointing moves
The
control until
the
10-arcsec
the target.
to place
that
combination
The light
angle
the
is calculated
coordinates
are
subsystem,
and
the light falls onto
passed the
by
Star-sky,
telescope
the correct
• The
spacecraft
ments aperture
to
place
may the
combinations.
repeat light
the in
small
adjust-
different
filter/
and
filters
study
However,
have two pairs of 0.4 and 1.0 arcsec which can be used for simultaneous
most
•
apertures, measure-
3-27
observations
the
Astronoto help
with
the
pin-
targeting
in a crowded
field
by the correct
can observe
which
which
uses
uses several the star's
of
filter
and measure
one
to study
rapid
another
IDT
the
sky at the
Polarimetry, filter.
which
aperture/filter
apertures
on one
brightness
of the background
od of time (minimum Two-IDT, which uses (usually
light from
aperture.
is acquired
to capture
brightness
filter.
aperture, chosen, to
ways:
•
filter
reposition
or interact
the HSP
Single-color, combination.
to the
target-acquisition
data
earlier
target
•
on the
that
to find the target
it in several
aperture
a
the largest HSP the image dissector
the correct
and aperture, The
plus
calculations
in the
is pointing
of the target the software
modes,
target
appropriate
already
observing mode.
and
sky over
is 10 millisec). one IDT for star changes
with the same same
the
a peristudy
in brightness) filter
type to
time.
uses the special
polarized
3.4.3
High
Speed
Photometer
Specifications
pulsars,
and
their pulsations
thousandths Table
3-5
High Speed Specifications HIGH-SPEED
PHOTOMETER
Pnncipal Investigator Contractor
R. Bless, U. of Wisconsin U. of Wisconsin
Apertures Resolution
0.4,1 0,10.0 arcsec 2 Filter-defined
Magnitude Range
< 24 m v
Wavelength Range
1200-7500 Ang.
ture tivity
and
can disclose the High
stars requiring
inherent
theories currently
will provide light-intensity determine stellar distances pulsars
and
serve
black
starlight
spheres
holes.
filtering
through
(occultation
sensi-
photometer
HSP
than
the
sun,
a beam
HSP
may
sars
atmo-
have
been
of the HSP.
HSP's
sensitivity
capture
these
The
can apply
luminosity
of light
stars because the
information
formulas
and magnitude
coming it has
a
faint-object is known,
to determine
of the target
the
astronomers can use, along with temperature color and other data, to calculate distances those stars.
or to
3.4.4.2
20
objects than
Search
for
astronomers emitting steadily.
Pulsars. have
radio These
waves objects
a cosmic
solve
some
Recently
light-
is shown
of the
mystery
a few visible
within
the
Astronomers
pul-
magnitude
hope
to use the
faint visible
In addition,
light to
the photome-
For been
nearly
HSP
of the light pulses
physical can
properties
information
light-varying, and Seyfert
high-energy galaxies.
objects, The
spiral-armed
galaxies
can
extrapolate
variations 3.4.4.3
that
vary
the
measured Occultation
planets
on
other
like quasars latter are in brightness.
may be caused by frequent galaxy's center. Astronomers core
diameter
by the
from
time
The
HSP
HSP.
Observations.
will record starlight occulted gases surrounding comet tails, System
to help de-
of pulsars.
provide
Seyfert pulsations explosions at the
star. By
observing faint and bright stars, the High Speed Photometer can contribute magnitude data that
years
rapidly,
ter can record light pulses as frequently as every 10 microseconds. The HSP also can record the
even
scientists
of a pulsar
to UV and
can measure
this
on
times
spin
like
pulses.
from
Once
stars
rendering
located
range
HSP
instruments.
as
based
A thousand
of energy
help
and color
than
models
neutron
pulsars.
the
range
created
hotter
termine
dynamic
down
of a dying star, perhaps 20 kiloThese stars are so dense that
intensity
greater
pattern, irregular observed
are slowing
exists only as neutrons.
surrounding
also will ob-
planetary
intensity
their have have
about the origin of pulsars. One model, in favor, is the neutron star, the small
3.4.4.1 Measuring Stellar Magnitudes. Astronomers must know how intensely a star burns before they can measure its distance. The the
in
matter
The
also
observations).
the brightest
few
Photometer
information to help and to search for
The
every
few seconds.
energy.
have
house. An artist's in Figure 3-28.
the tempera-
the ultraviolet
in the HSP. The
their
collapsed core meters across.
Speed
regular
gradually
Astrophysicists
spraying
of starlight
will observe
pulsars
they dissipate
Observations
of a star,
are
to every
some, called bursters, of pulses. Astronomers
that most
600 Ib (273 kg) 3x3x7 ft (0.gxOgx2.2 m)
The color
pulsars
though patterns
Weight Dimensions
3.4.4
Most
Photometer
vary from
of a second
by atmospheric stars, and Solar
and asteroids.
discovering
in pulses
rather
Two examples
now
called
can observe
are
3-28
are starlight
appropriate filtered
here.
The
HSP
by the atmosphere
Figure of Titan,
one
wavelengths astronomers
If
through field ods
intensity
is blocking
brightness
the properties
varies the
in starlight,
of time,
Uranus.
Some
light
by the gases,
Since
variations
the
light. the
Pulsar
3.5
The
passes
within
that
WIDE
most
is the
Wide
used
It can produce
over
peri-
tometric,
nine
around
short
rings
around
rings
WF/PC
with
wider ment
Neptune,
3-29
FIELD/PLANETARY
versatile
Astronomers
photographed
upon
the Voyager
of that
light
something
observed
to discover Voyager
as
Rotating
astronomers hope to expand discovery (see Figure 3-29).
and
atmosphere.
a field of matter,
variation
Visible
by the way the light dims as it passes the
light
moons.
can calculate
atmosphere through
of Saturn's
will be absorbed
3-28
and
of the scientific
Field/Planetary images
will obtain
Camera
instruments (WF/PC).
and spectrographic,
polarimetric
and grander to date.
CAMERA
pictures scale
measurements. of the universe than
any
other
phoThe on a instru-
Figure The WF/PC camera
has two camera
(WFC),
and
This is like having on the wide
camera. field
still would
(for need
the
WFC HST;
down
100 pictures
these
investigate,
two camera among
age,
the location
the
atmospheric
modes,
many and
to
shape
patterns
but it has 2.
how
of black of
Solar
and
FOC
cameras
with
four
will broaden
the scope
data.
The
will take
WF/PC
different
of the wider
func-
HST
visual
photographs
nearby
objects,
too
bright
for the
The
FOC
distance
such
as planets,
that
are
FOC.
a capability
is the
with sharper resolution. However, maximum field of view is (22 arcsec)
may
galaxies
holes,
two
tions
graph
angular objects
the WF/PC
things,
of WF/PC
of faint objects, without as much detail as the Faint Object Camera. The PC mode can photo-
but with limited
that are apart by only 0.01 arcsec, smaller field of view at (66 arcsec)
With
Having
It uses a focal ratio of of view of (2.7 armin) 2
to 28my,
Comparison
lens
camera
angular resolution. The PC has better resolution than the WFC, separating
Neptune
3.5.1
a relatively
wide-field
about
Around
(PC).
and a zoom
exposes the
to take
Rings
wide-field
or closeup
a wide-angle
photograph the moon). f/12.9 with a large field for magnitudes
modes:
planetary
The
3-29
and
System
to the
WF/PC
FOC,
for
within
a cluster
capture
planets.
3-30
(2.7 arcmin)
example,
can
of galaxies
the entire
cluster.
2 field
concentrate while
same,
but
the FOC's 2 compared of view. on
the WF/PC
The detail can
3.5.2
Physical
Description
The Wide Field/Planetary Camera 1.7 ft (1 x 1.5 x 0.5 m) in size, with radiator
that
unit weighs
is 2.6 x 7 fl (.8 x 2.2 m). The 595 Ib (270
the California the camera tory
kg). J. A. Westphal
Institute and
built
is 3.3 x 5 x an exterior
of Technology
NAS_/s
Jet
camera
configurations,
with
system; WF/PC
and a processing and send data
system to operate the to the Scientific Instru-
ment
total
Control
3-30 for WF/PC.
and
& Data
the
a cooling
Handling
radiator
unit. See Figure
overall
configuration
System.
The
of
the
system
for
designed
Propulsion
Labora-
3.5.2.1
it.
Optics
the WF/PC
consists
in the direct
optical
of a pickoff
mirror
line of the telescope
an
entrance
PC "pickoff"
ror to split the light; and fold and relay optics place the lights onto the CCDs.
pathway, into the instrument A, and between The eight
in the
middle
of the
filters,
focal
reflects the center of the light beam camera. The spectral range of this is the widest, from 1150 A to 11,000 the resolution objects
camera
will allow
it to distinguish
only 0.1 arcsec
is composed
charge-coupled
apart.
of an optics
detectors
(CCD)
gratings,
The
pickoff
light
path
the
with shutter;
light path;
The WF/PC is perpendicular to the HST optical axis, in front of the focal plane structure. A WF/ mirror,
aperture
inserted with
a pyramid
mir-
and polarizers;
mirror
is centered
of the telescope.
central
a carrousel
section
of the
diagonally The
mirror
beam
at a 90-degree
in two
length
of
exposure,
from
approximately
PIPES HEAD :)NICS -V3
RELAY
OPTICS
LIGHT
-_
EPOXY)
APERTURE MECHANISM
! '-" FOLD
+V3
MIRRORS
FILTERS t
-V2
FILTER CAROUSEL (50 FILTERS)
Figure
3-30
The
in the deflects
angle into the entrance aperture of the WF/PC. The shutter behind the aperture controls the
system;
HEAT
OPTICAL (GRAPHITE
to
Overall
3-31
WF/PC
Configuration
SEAL
0.1 second
to over
27 hours.
A typical
time is expected to be 45 minutes, half an orbit around earth.
exposure
parts, along CCDs.
or roughly
The
light
reflects
up to fold The
light
which
passes
contains
ducing
through
48 filters,
undispersed
diffraction WF/PC
lights
gratings,
and
can place
one
into the light path ple,
the
measure sure.
WF/PC light
The
carrousel,
for
lenses
three
See Figure
The
cal system.
of the
filters
or several take
assembly,
the
with
the WF/PC
3.5.2.2
For exam-
a photograph
during
array
expo-
mirrors,
or PC mode
is implemented
amid
mirror
to one
The
pyramid
splits
of two the
the pyr-
45-degree
angles.
light
beam
into
down
which
As the
from
the the
four
system.
incoming CCD.
These CCD.
of the basic
Detectors. is a silicon
are position
photons
pixel
photons
Each
detectors, the
charge striking
pattern later.
then
passes 3-32
will strike
._("_._
_::A:L
,
::i!T
! L_/7_
/
/
/--
/ /
of the light The charge through
illustrates the
pixels
f,_'_
PYRAMID
/ f-RADIATION
/f'_'-
/
..........
_,,,,
p
,_/
/-PICK-OFF
l Y'_i'-'ii_ii_''"''"':::::'_-!!!!!i_)ii_
RITCHEY-CHRETIEN REPEATER
_
--_
/
/
/
,/
PLANO _ RELAY MIRROR
/" /
,' OTA
,/
OPTICAL AXIS
,/ /
,,
/
f"
t/
•
Ie
s*'
/
/'
/
•
/ / / /
Figure
3-31
Wide
FieldPlanetary
3-32
Camera
Optics
Design
800 array,
proporit. This
f- SENSOR / ELECTRONICS //PLATFORM r- EXTERNAL / RADIATOR /
opti-
chip with an
bombard
Figure
back
the pyramid
mirrors. the selected
the intensity each
electronics
set of
mirror
past
the light is reconstructed
signal
the WFC
by moving
then
each pixel records an electrical tional to the number of photons
versatile
to use either
the pyramid
detector
ofpixels,
when the decision
to a specific
Charge-Coupled
will reproduce At this point
goes
3-31 for a diagram
on a side.
its overlapping
the most
from
charge-coupled
and
same
that
mirror and onto re-imaging focus the beam, finally, onto
pro-
polarizers.
targeting,
for dual functions. can
filter
filter clear
three
intensity
capability, makes of all instruments.
a four
a path
the how of
The
CCDs
such
a wide
are
powerful
spectral
nal, especially
range
for faint noise
from
interference.
The
spectral
phor
because
each
that converts In addition,
the CCD
is toward
trum.
The
heat
and
great
natural
(8002) from each when processed.
CCD,
3.5.3
of
view
and
image
either
WF/PC's
Within the
each
beam
Ii
/
!
Wide
Y
8O0
3-32
is minimized
WF/PC in each
keeps degrees
Imaging CCD
the CCD Celsius.
because
the
temperature
at a
a special
The
sys-
unit bathes
regularly
to short
cooling
Processing
the CCDs
to increase
is per-
system
and
the the
System.
CCD
the
This
Camera use
both
spectroscopy
for
spectra. specific
The wave-
photometry,
as well
as for filter
polari-
in the 2500-
to -8000
A, spectral
range.
Wide Field/Planetary Specifications
3-6
Camera
Wide Field/Planetary Specifications
with
WF/PC
has a
camera operaSI C&DH unit.
sets shutter exposure time, filter combinations, rotates
the
to select
a specific
mode
ultraviolet filters
WIDE FIELD/PLANETARY
The
basic
light
bombard-
photometric.
to capture also
of the
that
of the
the
basic
the WF/PC
detectors,
makes
and
The Because
intensity
Field/Planetary can
photometry,
since
target.
to study
Camera
the CCD
The microprocessor selects the required mirror
is imaging,
yields
are sever-
select
include
of the
of the
also
there can
metry
Table
wavelengths.
microprocessor that controls tions and transfers data to the
pyramid
of
length
3.5.4
tem consists of pipes that conduct heat from the CCDs to a radiator on the surface of the SSM.
3.5.2.3
acquisition
operation,
mode
uses a grating camera
sensitivity
field
photopolarimetry.
an image
light-producing
light
as
of view to capture
modes
and
ing photons.
ultraviolet
a separate
astronomers
These
construction
In addition,
operates or a planetary
guidance
field
camera
target.
records
8004
-95
has
Target
the HST
that
operational
INCOMING IMAGE
nominal
Camera
Each
generous
spectroscopy,
system
coming
target.
I::::::::::::::::::1
cooling
signals
a wide-field
resolution. using
al modes
Heat
the
Modes
camera.
formed
J
Figure
out
Field/Planetary
(cioseup)
640,000
to a single
Wide
two cameras,
end of the spec-
add
Operational
The
to visible
of signals,
reads
is
sensitivity
the infrared
path, and the CCDs.
by
with a phos-
photons
number
the sig-
accepted
chip is coated
optic from
electronic
energy
the
cover
is uncluttered
ultraviolet
photons.
they
and because
objects,
background broad
because
Weight Dimensions
595 Ib (270 kg)
Principal Investk3ator Contractor
J.A. WestphaJ, CIT
Optical Modes Field of View
camera
3-33
CAMERA
Camera - 3.3x5x1.7 ft (lxl .3x0.5 m Radiator - 2.6x7 ft (0.8x2.2 m)2 Jet Propulsion Laboratory f/12.9 0NF), t/30 (P) 160, 66 amsec _
Magnitude Range
9-28 my
Wavelength Range
1150-11,000 Ang
3.5.5
Observations
light-blocking ness
The Wide Field/Planetary Camera busiest scientific instrument on Space
Telescope.
With its variety
the WF/PC can perform observing a single object. focus
on
an
will be the the Hubble
extended
galaxy
and
take
picture of the galaxy, then concenthe galaxy nucleus to measure light
intensity
and
photographic
closeups
its "sun"
wobble
can chart
this wobble
sufficient
tary
the
Martian
Mariner
tains
verse
expansion
nova, comet, tant searches planets spheric galaxy amples
and are
in other storms,
star formation. below.
"hide"
behind
tational
pull.
become
a black
diameter,
the
hole,
often
the
atmosphere and other
of the
superdense
the black
of the hole,
until,
search
black
for
holes.
rendition
See
of
swirling Figure
a blue
to
disks 3-33
for
giant-black
binary
Field/Planetary instruments The
Camera
Systems. and
other
will study stars looking
WF/PC
pyramid
mirror
The
Wide
have
disappeared
by now,
affect
Collide.
The
process
When
Galaxies being
pattern,
A prime
When
this
happens,
sweep
through
tended
lobes
gases.
WF/PC
observation
evidence
and
huge
is when
in Figure
3-34.
shock arms
waves and
compressing
If a critical
gases
resolution
from
of this col-
tremendous
of the galaxies, the
of the
of gases
spiral
and
into
conception
capa-
a three-year
of a specific
of a star being
is
nuclear
spectrographic over
ex-
density
explode
could,
of
scientif-
believe,
the gaseous
the
gravitational
example
illustrated
The
periodically
the
astronomers
collide,
winds.
by several
with
ignition
clouds.
high
studied
climaxes
and nuclear
to the
after
they
galaxies ing gas
3-34
For
the Viking
how
more
3-35 for an artist's a
evidence. near
patterns
duce
scientific
dramatic
appearing
precisely
The
for planets. has
wind-
the wind
periodic in Other
spacecrafts
can study
bility Planets
lander
from
study of Martian
more
reached, coalesced life as a star.
system. 3.5.5.2
Pictures
WF/PC
compacting
of
artistic
Object
this plane-
of exposure
two galaxies
of the WF/PC
an
Faint
of years
lapsing
of
hole
should
interstellar
star.
as evidence
the
millions
collapse
in
a swirling
at the edge
to gen-
Storms.
Intense
ic instruments,
is part of a
create
time.
star formation,
core
companion
The
years
See
Viking
the craters
3.5.5.4
also may pull gases
elements
9 and
to calculate surface.
gravi-
the hole, all light disappears because overwhelming gravitational pull. The will
lander
Black
collapses
over
example,
ex-
only a few miles
the hole
The gases disk around
star
into it. If a black hole
star system,
from
Hole.
overwhelming
a dying
gravity
pulls all matter binary
a Black their
When
Those
path.
over
plan to attack
Dust
has not produced
super-
star systems, Martian atmoand the connection between
Photographing
holes
star,
planet studies. Some imporfor evidence of black holes,
collisions and are discussed
3.5.5.1
to specific
force
storms has astronomers and geologists puzzled because the erosion predicted by these studies
for the WF/PC range distance scales and uni-
theories
the size
clearly demonstrated that Martian winds sculpt the landscape, eroding the craters and moun-
observing. Specific observations from tests of cosmic
A planet
search.
3.5.5.3
center. In addition, the WF/PC can perform measurements while other instruments are
be plotted
in its orbital
evidence.
for a different
can
gravitational
enough
WF/PC Camera
of the
background.
can exert
of the bright-
path
to make erate
a
some
so its orbital
the starry
of Jupiter
while it can
wide-field trate on
take
against
of capabilities,
several tasks For example,
spot to mute
of a star
born.
target, See
proFigure
of this birth:
approach, then collide (top), until it ignites (bottom).
two
compress-
Figure
3-33
Black
Hole
in Binary 3.6
System
ASTROMETRY SENSORS)
When
two of the
(FINE
fine
GUIDANCE
guidance
sensors
(FGSs)
are locked on guide stars to provide pointing information for the HST, the third FGS can serve as an scientific instrument to measure the position
of stars
in relation
called astrometry, determine stellar
The They
Palomat
Figure
3-34
Two Spiral Colliding
Observatory
Photograph.
are
located
at right
Space
Telescope "pick-off"
stars.
fabricated in the
angles and mirrors
by Perkin-Elmer.
focal
plane
to the optical 90
degrees
to deflect
structure, path
of the
apart.
They
the incoming
light into their apertures. (See 2.3, Chapter a more detailed description of the FGSs.)
3-35
This is
and it will help astronomers masses and distances.
were
placed have
Galaxies
sensors
to other
2 for
Figure 3.6.1
Fine Guidance Table
3-7
Sensor
3-35
Time-Lapsed
Specifications
Fine Guidance
Star Birth
3.6.2
Operational
Once
Sensors
the
sensors
Specifications
sensor FINE GUIDANCE
485 Ib (220 kg)
Dimensions Contractor
1.6x3.3x5,4 ft (05xlx1.6 Perkin-Elmer Corp.
Astrometric Modes Precision Measurement
Stationary & Moving Target. Scan 0,002 arcsec 2 10 stars in 10 min
sure
m)
lock onto guide
stars
metric
Access: 60 arcmin 2 Detect: 5 arcsec 2
Magnitude Range Wavelength Range
target-acquisition
can perform
There
Speed Field of View
for Astrometry
stars,
fine
guidance
the third
guidance
astrometric
operations
on
targets within the field of view set by the guidestar positions. The sensor should be able to mea-
SENSORS
Weight
two
Modes
as faint
are
three
modes
position
for
mode,
astrotrans-
fer-function mode, and moving-target Position mode allows the astrometric
mode. FGS to
calculate
relative
be
the
measured
keeps
3-36
operational
observations:
to the guide
4-18.5 my 4670-7000 Ang.
as 18 my.
the
angular stars.
within pointing
position
Generally,
of a star
up to 10 stars
a 20-minute stability
of
span, the
will
which
guide-star
FGSs within 0.04 arcsec.
the
required
accuracy
3.6.4
of
Astrometric
Astronomers charting The transfer-function eter
of the
analysis
er
stellar
target.
either
System
planets, than
of the
latter
a
include
stars
visually
clos-
and
targets
sur-
arcsec,
by nebulous
direct
or by scanning
double
0.1
the diam-
through
object
Examples
together
rounded
measures
target,
of a single-point
diffuse Solar
mode
Observations
measure
its location
at different
times,
The
earth's
orbit
ent)
location
the distance
to a star
on two sightings nominally changes
from
six months
apart.
the perceived
of the nearby
star, and
(appar-
the parallax
angle between the two locations can lead to a estimate of the distance to the star. Stars are so distant,
gases.
of course,
quite
small,
that
requiring
the
parallax
a precise
angle
field
ally
measurements
separated
produce
by
of binary
more
than
measurements
ing to information gravity
in the
0.1
of stellar on the
stars
visu-
arcsec
can
masses,
importance
evolution
of star
tances stars
in our
objects,
called
because mode
measures
moving target relative to other not possible to precisely lock target.
An
example
angular
position
would
of a moon
a
rapidly-
targets when it is onto the moving be
measuring
relative
Each
FGS
Filter
measurement and wheel and
of stars
to classify faint-star
increasing ferent from
and a
contrast colors,
star
or
being
observed.
13my)
colored color
between reducing
related
to
important magnitudes
astrometry;
those
of nearby
faint
regular measure
for
nova the
by relating
to apparent shines), then
magnitude calculating
to
a
nearby
more
Cepheid
astronomers
can
Cepheids
with
faint
Cepheids
vis-
Telescope. Using this informawill calculate the distance to In
Cepheids
the
neighborhood
of
will be supergiant
and
stars. Astronomers distance to these
index,
from
close
of dif-
and supergiants are bright than Cepheids, they are excellent "distance standards" for measur-
background
light
ing greater
nebulosity.
3-37
Cepheid
distances.
comparisons.
can accurately brighter objects
(chemical) stars
the
can
to a Cepheid
between
Cepheids.
fainter
is
(absolute
Astronomers
because
and
reg-
pulsations
luminosity
distance
distances
notable
or pulse,
these
Cepheid.
periods the star
compare
the
of
the distance
becomes
are
and contract,
intrinsic
of the
ible to the Space tion, astronomers
The
used
the
the
acquisition
filters
nearby
that are consuch class of
variables,
frequency
Knowing
known
brightness
for observation
two
target's
for astrometric
for guide-star
Cepheid
the pulsation (how brightly the distance.
to its parent
different
than
filter
stars;
estimating
stars
filter
(greater
neutral-density bright
the
has a clear
with
The
determine
the
Wheel
FGS also has a filter wheel
beyond
stars, however, indicators. One
they expand
ularly.
magnitude)
planet.
3.6.3
method
galaxy.
There are certain sidered distance
planetary
systems.
Moving-target
parallax
of dis-
lead-
of stellar
and
by the
is
of view to
calculate the angle. Even with the precision the FGS, astronomers cannot measure Astrometric
by
earth
Since
novae
Section HUBBLE The
Hubble
Space
SPACE
Telescope,
once
TELESCOPE
deployed
by
4 MISSION Flight
operations
the Space Shuttle, will have a mission extending at least 15 years, based on orbital maintenance.
through Telescope
The
launched
HST
program
sion phases:
has
launch
three
and
operational
deployment
mis-
operations,
supported by the Space q'i'ansportation mission operations once in orbit, which the verification vations;
testing
and
Space
first
Hubble
Space
launch
of the
scope.
Chapter
tions
responsible
gram:
Marshall
project
Company
prime
strument developed
Center,
&
Corp.
and
a team
for of in-
development teams that designed the five scientific instruments.
arm will place
the
built
Systems
internal
Support
Telescope
and
Assembly
of the
built
of mirrors
Space
and optics,
Telescope
the
and sup-
Kennedy
Space
coordinated Telescope (STOCC) specific
before
Mission
crews
for its flight
cargo
bay.
mission flight Operations
its shipment
prepared
the
Space
the Shuttle
in-space
maneuvers may
remote
Center
and
Space
Tele-
manipulating
runs Shuttle the
posi-
the deployment will release the
HST will begin
oper-
operation
spacecraft tem and
it into
of
the
the in-flight
Space
testing
Telescope.
The
will undergo up to six months of sysinstrument testing and calibration to
determine
the
to 15 years.
Once
perform
concern
HST's
ability
to function
operational,
observations
for up
the telescope
selected
and
will
supervised
by the Space Telescope Science Institute. The Payload Operations Control Center will handle commands
tus-signal the latter
processing, and with the Institute.
the Institute Support
and
and
operations,
sta-
mission scheduling, The liaison between
the POCC
will be the Science
Center'.
During its life, the Space Telescope with certain defined characteristics, much
time
it spends
orbit,
or maneuvering Telescope,
in the earth's and
will operate such as how shadow
viewing
for example,
within 50 degrees of the sun when unless the sun is behind the earth, the HST.
each
constraints. cannot
point
maneuvering as viewed by
Center
plans with the Space Control Center
and trained
vehicular activities that the Shuttle lifts off.
the
under
and loaded
Johnson
launch
the HST into orbital
and
operations
The Space
prelaunch
Telescope
Shuttle
tested
for durability
liftoff and orbit conditions, to Kennedy Space Center.
the
some
Perkin-Elmer
instruments,
completed
the
and
structure,
structures, as well as the three fine guidsensors. Then Lockheed assembled all the
components,
At
outer
Module,
equipment.
Optical port ance
the spacecraft's
for the
the Shuttle's
the STOCC Finally, the
spacecraft Lockheed
Space
required
system
and
for overall Missiles
Perkin-Elmer
responsibility;
the orbit Then
from
the Tele-
of the HST pro-
Lockheed
and
contract
Space
the organiza-
for that phase Flight
with
the
5 lists completely Space
the
Kennedy
scope.
tion as sequence.
the period
which places the Space The Space Shuttle will be
of the
concludes
carrying
from
Space Telescope, ating on its own.
development
Telescope, Shuttle
over
in orbit.
phase,
management;
Space
operations
lifetime
program
obser-
cover
deployment, into orbit.
establish
System; includes
the scientific
maintenance
Telescope's
The
and
DESCRIPTION
astronauts
for
and
extra-
be required
once
4-1
In the
maintenance
and
the Shuttle can bring up ment on a maintenance Space Telescope it back to earth
refurbishment
phase,
replacement equipmission, move the
to a higher orbit, or even for major overhaul.
bring
4.1
LAUNCH
The
launch
place
AND
through
the Hubble
checking sections
DEPLOYMENT deployment
Space
out the HST systems. discuss the launch and
the Hubble
Space
Telescope
planned contingencies could arise.
4.1.1
Launch
Prior
to launch
with the
flight
deck,
after
The following deployment of
in detail,
for
from
Hubble
switch
will
in orbit,
including
emergencies
that
and Predeployment
cargo bay, the communication dard
operation
Telescope
Kennedy
Space
Space
Telescope
Center,
in the Shuttle
Orbiter will provide power and for the HST. The Orbiter stan-
panel,
located
will control
in the
power
Orbiter
aft
to the HST
until
the spacecraft is deployed. Essential power the HST will come from the Orbiter through external connects
power line called an umbilical, to the HST aft bulkhead.
fixed-head
star tracker
prevent antennas
contamination and solar
addition, rate
the
sensing
At
launch,
330
nmi.
inclined
will be closed
to
during launch, and arrays will be stowed.
multiple-access
the
Shuttle
receivers
km),
will
Center's
the In
and
from
TX, will confirm lifting
to an
or
Mission
the Shuttle
lift
plus
at 28.5 degrees
Houston,
which The
the
unit will be powered.
(607
son Space shows
shutters
to an
orbit
minus
of
5 miles,
the equator.
John-
Control
Center,
the orbit.
Figure
off the Kennedy
Figure
4-1
launch
Predeployment
After the
establishing cargo
space. start
bay
up the
The
crew
and
expose
two
hours
later
telemetry
device
Operation
the
doors
interrogator
nication
Checkout an orbit
Roughly
payload
HST.
main hours
that
Control Orbiter
systems links
the
Center will send
the
and
(PI). The
will open HST
the
crew
the
Shuttle
to depressurize. HST thermostatic
keep
the
internal
vival
temperature
components
levels
above
as temperatures
surdrop
to will
Orbiter
For the
rest
will turn
of the
on the
Space
Telescope and
electronics
assembly,
deployment
control
the HST
4-2
interface
first
data
unit/science
to the
at least four system com-
in space.
data
power
Off
The STOCC will turn heaters so they can
HST
PI is the commu-
(STOCC)
Lifting
power buses after waiting for the HST communication
ponents on the
pad. 4.1.2
4-1
in
units, data
flight
day,
the
management tape
formatter, rate
STOCC
subsystem,
recorders,
control
pointing/safemode gyro
electronics.
assemblies, The
and
STOCC
will
monitor,
computer systems data
via
telemetry,
memory undergoing
and
testing.
go to the
PI, then
Satellite
System
Relay
the
contents
The
through (TDRSS)
to each
If necessary, could
other
telemetered and
positions of the Orbiter
and to the earth's
telemetry
solar arrays the formal HST
low-gain
directly
Contingencies Predeployment Launch.
Telescope
verification.
Placement
in Space.
If the Space
subsystems
begin
the
antenna
crew will connect the RMS to one of the grapple fixtures on the forward shell. The RMS will lift HST
neuver
and
out thoroughly
diately
before
shutters
must until
4.1.3.2
instruments to launch.
the external
the HST and the fixed-head If there
areas,
the STOCC
the
problem
to the
automatically to internal
batteries
hold
the Orbiter •tern (RMS) system
tests
would
place
power.
operation power,
Tele-
Because
the
the
3.5 hours, deploy
manipulator solar
perform
the sys-
arrays. the HST
before
contingencies with the HST.
the
the
crew
Telescope
will include lifting
space.
umbilical
immediately
conducted
day,
Space
maneuver-
be
deployfail, the
Deployment
the
RMS
the
delay
cannot
for only about
the STOCC
normally
second
into
the
ma-
above
are
Figure
On the
4-2 shows
bay and
Imme-
the Space
it by the remote
ment. If predeployment Orbiter would return
4.1.4
position
the crew can disconnect
battery
a charge
would
cargo
will
Orbiter
problems
the Orbiter
arm, and activate
Only then
Shuttle
The
umbilical
were
switches
crew would
HST, holding
HST
STOCC
the crew will check the If the umbilical is con-
but not working,
it. This
of the
it to a precalculated Figure
the
Orbiter must star tracker
If power
HST from
prior to deployment, umbilical connection. nected
out
out,
procedure.
is resolved.
Predepioyment.
applied
deployment
Space
and
be closed.
in any of these launch
Hubble
prior
the launch,
power line between be connected, and
scope
on-board
check
Tele-
scope
Orbiter.
equipment
checked
telescope
shadow.
to TDRSS.
for Launch
The
the
for orbital
ing the 4.1.3.1
extending
will be ready
4.1.4.1
the 4.1.3
and
and antennas. This will complete launch and deployment, and the
to the STOCC.
the HST forward
send
bay with the RMS,
activated
the Tracking
Transmission will depend upon the the communications satellites and relative
DF-224
the
in
switching
spacecraft
will
out
prepare space.
to This
to HST
battery
of the
Orbiter
4-3
4--2
RMS
Maneuvers
Just before placing the HST will switch over power from HST batteries. At the same the Orbiter conserve which
HST
in space, the crew the Orbiter to the time, from within
the crew will turn offHST power,
removes
then
disconnect
the Orbiter
power
heaters
to
the umbilical, connection
to
the HST.The HST nowwill beon its own power, driven by the batteriesuntil the solar arraysare deployed. 4.1.4.2
Deployment
STOCC
must
high-gain
of
extend
antennas
er-accumulating
Appendages.
the and
and
solar get
and
HST
point
within
communications
in the
extension three
hours.
deployment
systems
two
the
STOCC,
will extend
The
solar
LIFTING
HST
crucial
will be the
arrays.
For
by remote
and test the solar Orbiter visual
most
procedure
of the
hours
nas. The STOCC
6.5
ARRAY
........../ .....
pow-
I 1 ) RMS
operating
SOLAR
The
arrays
the
_--
about
command,
arrays
\ \
\
and anten-
\ ]
crew, meanwhile, will give the confirmation and film the
HIGH
GAEN
ANTENNA,
procedure. The
solar
array
1.
Positioning
deployment the HST
will involve: so that
the solar
RMS(TOWARD
array 2iPR!MARY
panels
will
delayed
face
until
the
the
sun
HST
(this
could
is in full
VIEWER)
_DEPLOYMENT.SA
be
sunlight)
(30 min). 2.
Releasing using
the array
the
SSM
forward
and
mechanism
aft latches
control
unit
(5 rain). 3.
Raising the masts ment mechanisms
4.
Unfurling
the
with the primary (8 rain).
+ V2 solar
the secondary (5 min).
array
deployment
deploy-
blanket
with
mechanism RMS
5.
At the same cal power current
6.
time,
commanding
subsystem
charge
power.
Turning
the
on
(EPS)
controllers
can receive
the electrito turn
so the
Figure
OTA
and
battery
heaters
the
-V2 SA blanket
(5 min).
4-3
aperture
the antennas ow portion
Figure solar
4-3
illustrates
the
deployment
of
the
arrays.
Deployment
simultaneously. The
Deploying
DEPLOYMENT-SA
batteries
again. 7.
3)SECONDARY
on the
be opened ating,
of Solar Arrays
This will take door
latch
are being
extended, The
until the coarse the
10 minutes.
will be released
of the orbit.
to protect
about
door
during itself
sun sensors
aperture
from
while a shadwill not
are operexcessive
sunlight. At this point control When STOCC
the STOCC
subsystem the
crew
will erect
will start
magnetic gives
visual
the high-gain
the pointing
sensing approval, antenna
system. the booms
4-4
The STOCC will begin slewing tests to make certain the solar arrays move and position properly.
Again,
the
crew
will give
visual
verifica-
tion.
The
entire
deployment
because of verification three hours.
begin
procedure,
tests,
may
take
over
early
NSSC-I door
pointing
computer
Release
into
arrays
supplying
turning
on equipment
deployment
Orbit.
power,
With
the
not
the
begins
earlier
in the
The
HST
the
RMS.
into
now will be ready The
spacecraft's
the
RMS
Figure
RMS
will will
move
will adjust and
control
position. release
to be released
arm
attitude,
the attitude
the
Orbiter
45 hours
DF-224
will
in case
remain
aperture the
Space
nearby
for
the
next
of emergency.
the
the away
the
HST
STOCC
will
system
Fifteen
to monitor
minutes
spacecraft from
from
later
and
the
HST
the (see
4-4).
the
Deployment
deployment
overrides for HST
internal
manually.
commands computer's
now
will
"keep-alive"
Figure
start
up
monitors
4-4
HST
the and
Released
4-5
The
the trunnion is
Orbiter
not turn
would
astronaut switch
receive on
go into control
vital
on
to
Figure
Moves
internal
maintain 4-5 shows
ing on the power.
and
do can
the the
panel
Away
power. the
of
manual
Telescope
deployment,
bay of the SSM equipment
manually
temperature.
crew
crew
the
Space
before
systems the
locate
and
If,
Many
will use
built into the Hubble
immediately, bay,
Contingencies.
contingencies
emergencies.
power STOCC
after
process.
its correct
activate
up. The
hours
is in orbit.
Orbiter
4.1.4.4 The
24
SI C&DH
solar
STOCC
needed
The
will power
will be opened
Telescope 4.1.4.3
procedures.
the power power cargo inside section, HST correct
the crew switch-
II I
Figure
4-5
Crew
0If temperatures
EVA
begin
by Control
dropping,
the
can change orientation to improve ture of affected instruments.
If the RMS does
Panel
not hook
onto
Orbiter
the tempera-
Figure
the SSM grapple
by remote control, nection manually.
the crew can make the conIf the RMS fails completely,
it may be possible
to unlatch
the crew Figure into
the HST
push the spacecraft 4-6
shows
the
out of the Orbiter.
Orbiter
rolling
HST
ally.
the solar A crew
wrench
arrays
or the high-gain
the crew can deploy member
into a fitting
would found
drive
mechanisms.
then
crank
each
drive
the
arrays
a crew
quickly member
primary
by hand
if needed. erecting
manu-
a ratchet
The
solar array is erect and the wing The astronauts also have power
anten-
them
insert
on the
secondary could
If it appears damage member, member drive
and
astronaut until
the
is extended. wrenches to Figure a solar
4-7 array
that
could
the
remove
mechanism
array
wing
solar
the HST
array
it.
NASA
has
Figure
wing
may
to
tions
delaying
ring on the SA hull and push
4-8
the solar
planned
maneuvers from
a clamp
on the HST
away.
unbolting
soning
shows
array
a number
prevent
any the
the
a crew
before
jetti-
of workaround unexpected
release
situa-
of the
Space
Telescope. If the HST cannot atures,
systems
maintain could
within
the
spacecraft.
mary
mirror
could
if its mounts ronment.
4-6
Orbiter Rolling Out of Bay
the HST or the Orbiter or injure a crew the array can be jettisoned. A crew
member
nas not deploy,
shows mast.
the
space.
Should
erect
and have
4-6
affected
temperseriously
example,
be permanently
contract
If there
be For
internal
in the cold
is no internal
the
pri-
damaged space power
envito run
the
heaters,
attempt
the
crew
to reconnect
and restore
the
thermal
scope.
Then
study
and
the
immediately Orbiter
power
STOCC
correct
will
umbilical
to the Space would
the
have
Tele-
time
internal
to
power
problem. •
If the HST cannot one
SA to begin
must retrieve then can
manually
or rotate
masts
slew
maneuver umbilical. Before
HST
the
batteries,
the spacecraft. extend the SA them
to face
HGAs,
redeployment,
if
also
can
grapple,
the
and
crew
umbilical
If the batteries over a limited
must"
to recharge the SA
discharge past a certain point time, they cannot recharge and for
power
vital to the operation earth
shadow
duce Failure cel the
storage.
because
the
of any of these mission. Return
workarounds
to Earth.
Should
the remote
to the
manipulator,
HST
so external
3.
The payload commands
4.
The
interrogator to the HST to the
Orbiter
4-7
it be necesthe
following
all bay
and remote-
power
can replace
will send STOCC and return status
ground.
will
maintain
control within the HST is returned to earth.
Array
can-
power.
telemetry
Unbolting
could
ly latch down the telescope via the trunnion control panel. The crew will attach the Orbiter umbilical
HST \
pro-
Crew members will stow or jettison appendages, place the HST in the cargo using
2.
are
it is in
SAs cannot
sary to return the HST to earth, procedure will be performed: 1.
They
of the HST when
power.
4.1.4.5
Crew Member
Crew masts
correctly
Crews RMS
the Orbiter
will be useless
4-8
the
SA Mast •
Figure
at least
the batteries so they do not fail before produces enough power.
i!
Erecting
deploy
improperly.
the
reconnect
4-7
charging
Shuttle members the
Figure
successfully
until
temperature the
telescope
.
Just prior will close
to re-entry, to protect
the cargo bay doors the HST, and the
STOCC
will shut down
thermal
systems.
the HST
power
and
goals.
The
Center
Space
ter will run support
MISSION
Mission
OPERATIONS
Operations
six months,
covers
designed
Telescope
systems
function,
and
and
the
the testing
to verify scientific
science
and
Once
Telescope
verification. tems and
and
the STOCC
and
Verification
OTA
subsystems
End
Scientific
their
systems
to
orbital
checking the test ments. This data by the
4.2.1
Mission
the SSM
to stretch
Item (CEI)
(SV)
simi-
testing
will
approves
the HST
will have
a high
as each
priority,
instrument
and becomes
systems.
orbit,
ready
for Orbital when
the
system
operations,
such
Space
Figure
Telescope
activities
in the
Space
Telescope
Science
coordinating astronomers
The
passes
third
its system
section
The in-
Scienwere
on deployment.
Verification
(OV). The
make
up the Support
Systems
Telescope
for science
STOCC
Assembly
the STOCC
operations.
in number
lowing
summary
focuses
pointing
control
subsystem
testing HST time as point-
intense
verification
(STScI),
in Baltimore, Md., science operations,
will face strentests will be inter-
to change.
on the
process
4-8
The
fol-
testing
of the
as an example
of the
the subsystems
the
Orbiter
releases
the
HST,
will
the
tele-
scope will be in an imprecise orientation. The HST will be under Software Sun Point Control, means
sunlight
The
that
its attitude
on the solar
pointing
control
arrays
places
maximum
for power.
subsystem
compo-nents
will be turned on. The components tested to calculate and transmit data
the efforts of many international with different and overlapping
them
undergo.
After in
and subject
subsysModule
will approve
These
operations
is charted
Institute
leaves
milestone the HST in
Orbital
and Optical
4-9.
at John Hopkins University will schedule and oversee
HST
struments perform tests required to pass tific Verification. The first two milestones
which The
set for is the
tests and completes Orbital Verification. fourth milestone will be when the scientific
tems that
ing (slew) maneuvers or on-board engineering calibrations. The planned daily time allotment for
the
Verification.
telescope
complex,
its calibration Sharing
before
linked,
increasing
fully functional.
will be many
as the
milestones first milestone
the Orbiter cargo bay. The second will be when the STOCC stabilizes
4.2.1,1
by the instruearly database
Science
passes
Missions
and
observers.
begin
ground
HST
(MOC) at Goddard, communications and
to be completed
discussed
calibrat-
specifications
guaranteed-time
the
specifi-
instruments,
data produced will form the
operations
Telescope
as the
that
two orga-
Verification
uous tests before Overall
the Space
Contractor for telescope
will occur
Verification.
Verification meet
operations These
serves
Cen-
mis-
orbit
will begin
rigorously
to Contract
limits.
used
enters
will operate
larly will test the scientific ing
of the
Scientific
(OV)
subsystems
Operations responsible control.
system
Control Flight
operations.
There are four sequential Mission Verification. The
Space
Orbital
cation
op-
This is a thorough check of all sysscientific instruments. It has two
phases: Orbital
of
Space
Lockheed
Space
instruments
remainder
on its own power,
the
engineering
erational period of the sion, at least 15 years.
the Hubble
period
that
day-to-day
comprise
system.
Operations
at Goddard
the science
nizations 4.2
Telescope
(STOCC)
will be to move
6O SCIENCE
DATA
_0
40 SCIENCE RELATED ACTIVITIES 55%
30 I---
HST ON HOLD
PRIME SI OBSERV 35%
35% 20
10
m
D
SAA** ENCOUNTE R WHILE ON HOLD 12%
_
ACQUISITION
GUIDE STAR
_
ACQUISITION 5%
PREP 9%
/--SAA'" _
ENCI_NIE 1.5%
1%
"F"
PARALLEL SI OBSERV 22%
SLEW1NG 9%
ETC.* 1.5% TARGET
R
Sl CALIB 4%
NOTES: ° INCLUDES FHST UPDATES. INITIATION OF TRACKING. OTA/SSM CALIBRATION. *' SSA IS THE SOUTH ATLANTIC ANOMALY WHERE RADIATION BOMBARDMENT IMPINGES ON SCIENTIFIC OBSERVATIONS
Figure the
Space
Telescope
for communications
into and
4-9
a better
Time
orientation
telemetry.
Allocation
ETC.
for HST
based
on
means
the high-gain
the
to transmit First
the
fixed-head
mapping
the
general
Meanwhile,
the
accumulate
data
relative
star
to the
magnetic on the earth's
gyro assemblies pointing attitude
trackers
will
begin
location
of
stars.
sensing
system
telescope's magnetic
track
rate
will assess the Space Telescope (with respect to a stable refer-
ence system) and its rate of angular circles the earth. The coarse sun keep
The
of the
sun's
motion sensors
Tracking and Figure 4-10).
data,
as it will
position.
12 hours, produce gyros.
accumulated will
updated The
HST
go
to
over ground
position will adjust
more
than
computers
coordinates its pointing
which
antennas status
Data
then
signals Relay
in turn
will be able
to an available Satellite
(see
The STOCC then will take the Space Telescope out of Software Sun Point Control and allow the rate gyro assemblies to control ing (orientation) in orbit. The
NSSC-I
the
instruments
Over This
system
coordinates,
will
orientation field.
new
computer
day the rate
to
for the (FGSs).
On
STOCC
checks
4-9
begin
to improve
for the attitude,
will be turned
can
the next
be sharpened
operation the
the HST
on so that
verification gyro
fine
guidance
flight
day,
door's
will
and prepare
third the
tests.
alignments
telemetry
of the out
point-
sensors after
bright-object
the
Because
"x
each
from
the heat
earth
shadow,
tional
and
"cold"
orbital
effect
\ \
\ \ \
of solar the
pointing,
actuators
the
system,
Space FGSs,
the
scientific
the
aperture
Telescope
now
door
key to placing
instrument
will open.
will be ready star
to test
images
in the
apertures.
pointing
control
of the fourth
will be turned flight
will complete assume other devoted and
mapping
full range
this
phase,
the
secondary
the
STOCC
Telescope
assembly
Refinement
of the
tem will continue tests
to assure
Scientific
align with respect and each other.
to
the to the
the
system
is subject
warrant,
but OV will and retesting.
Verification.
once
tem
its verification
the
will test
The similar
pointing the
pointing
however,
Scientific
begin
after
Orbital
Verification
The
STScl
will
be
Space Flight Center ance of the scientific
scientific testing
control
tests.
of an intertwined
at Goddard
will entire
Verification
all will undergo
as part
the
until
type of testing
calibration,
•
the Orbiter
and
subsys-
In fact,
some
system
capa-
series
of tests.
Verification
will
is completed.
responsible
to
Goddard
for the successful performinstruments. The SV man-
will run
the verification
set of objectives
with a
to:
the
eleventh
•
distortion.
adjustment
gQidance Space
Optical
day, sensors
Telescope
sys-
axes
•
how
the
science
HST,
and
requirements
equipment
accuracy. Fulfill the observations ers.
4-10
that
scientific are
If the
can
first
two
and
needs
of
perform-
plan
work-
against which other measur-
compare months
data of
by the guaranteed-time system
instru-
capable
system
Develop calibration standards the scientific instruments and ing
as will can
Decide
ances fail arounds.
of
adjusting
in the
remove path
end
Demonstrate
ments, and guidance sensors effective scientific work. •
tracking
will practice
into-the that
Toward
actuators
optical
of Orbital
4.2.1.2
STOCC
for
on at the beginning
the HST FGS coarse
mirror
The
specification.
as circumstances
passes
by moving
process
subsystem
this general
ager
day. At this point
calibrations.
retesting
follow
its standby mission and can duties. The next three days will be
to testing
and
on the quali-
accordingly
its performance
specific The first FGS
have
and retesting.
this
Generally,
detection
"hot"
tests will tell what
variations
positions
continue
bilities
The
during
These
opera-
the
focal
instruments
Its Orientation
the
adjust
to change
HST Adjusts
into the cold of
systo
The
4--10
telescope
will test
systems
periods.
instruments
Figure
the
exposure
STOCC
temperature
meets
I
will plunge
ty of the light reflected through the optical tem. The STOCC will use this information mirror
\
orbit
additional
for
scientific observtime
for
verification, the guaranteedprobably will be extended.
observer
time
brated
more
graphs
and
more Astronomical
calibration
standards
will be used
to measure ultraviolet example, astronomers
and visual light. For will point the HST at
nearby
with known
celestial
objects
and compare these instrument detectors.
against
calibrations
readouts
by
the
are
ments.
most
efficient
instrument level
through
the pointing above. Most
system scientific
ple functions,
either
ters or focal/optics each
must
a process
through
tions
as possible.
share share
or overlap verification
The
like
described have multi-
use of different
or both.
will exercise
to its
much
fine-tuning instruments
paths
instrument
be tuned
The
as many
The
instruments
observations, tests.
often
so they
will
will also
Verification,
to play
and the
Mission Space
Operations
1. 2.
operations,
celestial
objects
overall
calibration image There
lamps
being are
could
from
types stray
filter
interfere
verifica-
wheels
or
with
the
instrument.
of interference lamplight
to
reaching
detectors; indirect, from motion (jitter) of target beam as wheels rotate. Instruments
will be tested
in tandem;
e.g., the FOC
and HSP
together.
The
science
gets, mixed observations.
tests will study
in with guaranteed-time Since the two cameras
fulfill
the
mission
in two
which
will
and gather
data.
and engineering
wavelengths
of
types
of
observe
operations
against
during
Mission
operations
often
wavelength
Scientific
stan-
Verification.
specific
tar-
science will be cali-
4-11
are carried system,
out by the Space
which
and
consists
Space Center.
of the
Telescope The STScl
oversees science operations. The Institute hosts astronomers, evaluates and chooses observation
programs,
schedules
observations, received from the
day-to-day
the
Payload
operational Operations
Goddard
Space
interacts
with daily
the
selected
and stores and analyzes data the HST. The STOCC makes all
Institute-staffed of the science
be
coincide and interact. For example, a scientific instrument may observe a star and calibrate
make Many
will
schedule
of the
by another
two possible
test for -- direct, the the
that
recorded
sensors
performance.
Institute Control
has
all five
On-going engineering operations, which will calibrate, test, and maintain the HST's
ground
instrument
--
in observations.
program
Science
Science Operations
scientific
so it is
of Scientific
before
guidance
Telescope
Telescope
Each
period
roles
lowing test captures tion process.
flavor
photometer
apertures,
probably
major
changes prevent publication of a complete list of scientific verification tests. However, the folthe
the
Operations
incoming possible
camera
much
The apertures
and
the five-month
dards developed As with Orbital
the earners.
the
spectro-
expects
operations:
of
combina-
After
and
fil-
testing
than
instruments
the scientific
from
--
4.2.2
Each
data
Verification
will gather information and to select the second ments.
the complex NASA
expected to take longer to place the image onto the small apertures and calibrate these instru-
ready
plans instru-
than
two spectrographs
smaller
In addition to the above goals, the STScI will develop improved operating procedures. It also for maintenance set of scientific
early
for the
quickly photometer,
Flight the
quick-look
data
and
the science functions.
data.
Figure
through Center
Center.
The
STScI,
Science science
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at the
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Figure 4.2.2.1
Space
Space
Telescope
Telescope
to Goddard
Science
for the
4-11
Science Institute
science
SCIENCE
CENTER
ENGINEERING
"_
Space
Institute.
Telescope
The
is responsible
programs
on the
Hubble Space Telescope. It is operated by the Association of Universities for Research in Astronomy (AURA), States universities national
facilities
a consortium of 20 United that operates several
for astronomy.
Ground
It will also
Examples quality, focus.
will solicit
tion proposals
and select
tied
STScI
out.
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observations ducting facilities archive,
and
observations. and and
software distribute
observations
will plan
assist
all observa-
guest The
and
science
HST
NASA
Telescope representing
in con-
community.
provides
reduce,
and
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schedule
observers STScI
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to be car-
monitor
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and review
REQUEST
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pointing
tific goals Institute
COMMAND
Space
Telescope
and
scientific instruments for any characteristics that could affect the collection of science data.
the The
INSTITUTE
Goals.
instrument
performance
inaccuracies,
The
program
STScI
and
will help
to meet
the
of the HST program, in consultation Institute the
telescope
overall AURA2s
and
international
scien-
set by the STScI
with
Council
conduct
Space
committees astronomical
the
analyze,
data.
4-12
Some
of the scientific
scope
are:
goals
for the Hubble
tele-
•
Calibrating
distances
objects using ments and a candles." • •
Determining
at what
the universe
is slowing.
Gathering
to
improved series of
astronomical
parallax distance
rate
the
information
about
photographic
and
GSSS
measure"standard expansion
star
star catalog
celestial
objects,
graphic of
formation
has information
survey
Figure
created plates
from
covering
4-12 is a photograph
catalog.
It shows
rounding
stars
on 20 million photo-
of a portion
a spiral
in that
1477 the entire
galaxy,
M51,
sky. of the
and
sur-
sky sector.
in galaxies. •
Making observations
of embryonic planetary
spectroscopic
stars (protostars).
•
Finding
•
stars, through imaging or astrometry. Resolving dense star-cluster nuclei in search of massive black holes.
•
Discovering density,
the
Institute
(SOGS) computer contract
Computer
Science
halos,
interstellar
hardware
role
and
in the Institute's
Operations
(GSSS)
created
Ground
the Guide
used
by the pointing
control
ence
Data
Software
vide
analytical
Analysis tools
for
the processed data. GSSS and SDAS.
ers,
the
System
is a data- management and scheduling system, developed by TRW under to NASA. The Guide Star Selection
System
SOGS,
temperature,
and
play an important The
nearby
of gas in galactic
clouds,
Software.
software
of
composition,
and structure
high-velocity medium.
work.
companions
designed
handles
observation routine
(SDAS)
STScl
to use six VAX software
processing.
grams will perform run the science
studying
developed
and
Sci-
will pro-
11/780
planning
support, data
catalog The
astronomers
The
science
Star
subsystem.
the
comput-
scheduling,
support,
Together
and
these
the computations operations on
pro-
needed to the Space
Telescope.
Figure
After
use SDAS
so the scope stars
Star
Selection
reference fine
accurately. that
sky when
stars
guidance
and other
sensors The
GSSS
can be located the
System
sensors
(GSSS) bright
can point
objects the tele-
will select
unambiguously
point
the
will
telescope.
data,
application their
Selecting
Observation
astronomy
teams
team approach decision rests
proposals
and
will be able
programs
to analyze,
Proposals.
to and
feasibility,
are than
The Institute
by evaluating
and choosing the Since individual
more
measures,
data.
technical
reviews, posals.
edits, observers
observations
guide
4-13
collects,
science
in the The
A Portion of the GSSS Star Catalog
interpret
will select
Guide
provide
SOGS
archives
for The
4-12
requests
conducting
peer
highest-ranked astronomers
proand
expected can possibly
to submit
many
be accepted,
is being encouraged. with the Institute
a
The final director,
advised by a committee other scientists.
The
first
priority
principal
for
of astronomers
SOGS
and
observations
investigators,
those
astronomers
who
The principal tions are:
investigators
designed
goes
to the
scientists
and
the and
instruments. their
R. C. Bless,
University
•
Speed Photometer). J. C. Brandt, University with GFSC
of Wisconsin
(High
such across
of Colorado,
(Goddard
High
for-
ARC
(Faint
E
Macchetto,
STSCI •
J.A.
Object
Westphal,
tary
principal
between
can The
within
24
The
package
is written
soft-
computer
be formatted
plots,
and negatives.
the
archive
data
all data
SDAS
Agency/
addition,
individual
aged to bring and reference
Field/Plane-
and
are
other
guaranteed
and
photo-
Institute
hours
plans
after
it is
so observers
can
images received by the transferred to SDAS. In observers
their own data.
8 and
19, 24%
for the
12% for another
10 months.
rest
the
observing
the
reserve
10%
time,
for special
unexpected
events
12
Of the
director
observations,
celestial
next
will
such
as
(targets
will be
encour-
data-analysis
software
Selected
scheduling
Observations.
consideration
target,
stray-light
The primary
limited
by
environmental
An example
would
faint object that must be observed when HST is in the earth's shadow. The schedule take into consideration tions that use more required
time Analysis
retain
data
Computer
and in its
resources
computer
and be a the will
observations.
Storage. archives
The after
will include
facilities
analyzing the SDAS
from
system
status
of data
age banks. Observers will be able to retrieve examination dures that
for storing the
HST.
will record
as it pours
the
A datathe
into
loca-
the stor-
and visiting astronomers the stored data easily for
or use in data-manipulation can be created on the
proceInstitute
computers. In addition
to the
will
engineering
store
will it. and
to be selected.
4-14
on
example,
that
able
in certain
to
science
for adjusting
based data develop
data,
the
data.
computers
This
Space
can
Telescope
be
opera-
engineering
findings
--
instrument
provides
unreli-
an more
temperature efficient
ranges use
of
for
-- and the
HST
systems. 4.2.2.2 Center.
STScI
expected
management
tion and
tions
system limits, observathan one instrument, and
for special
data
important
will be the availability
constraints.
base
will be responsible
of
opportunity). Scheduling
Institute
massive of
time for the first three to seven overall verification, then 34%
months
of
guaran100%
and
other
prints
on
printer
Space
months,
Data
the
reports,
to process software and
(Wide
investigators
observers
the observing months after
a
data
detector's
Then
Camera).
teed-time
of
which
in the field.
to process received.
The The
the
interact SOGS
Camera).
Cal Tech
from printed
data
Spectro-
European
(Faint
the
Object
graph). •
data
automati-
Resolution
Spectrograph). R. J. Harms,
science
then
as variation
will place
graphic
Facility,
and verify the quality of the data. It the data to remove instrument in-
sensitivity ware
contribu-
will receive
Capture
terference,
tapes,
•
•
the Data
cally format will calibrate
into
merly
data-processing
from
Space The
Telescope
STOCC
craft operations the Payload (POCC),
the
Operations
will run
day-to-day
through three Operations Science
and the Science In addition, the
Support
Data Capture STOCC works
Control space-
coordinate Control
parts: Center
Center
(SSC),
Facility (DCF). with the NASA
Communications Tracking (TDRSS).
Network
and
Data
(NASCOM)
and the
tion that reflects
Satellite
System
operation telemetry
mission-control
facili-
Relay
POCC
will use
ties at Goddard. many
times
the
These
before,
facilities
International Ultraviolet missions in the 1970's. The
POCC
have
including
will have
the
port.
telemetry
Mission
science
and
POCC
been
used
fect
the
and
take
steps
spacecraft
to a
five major
operational
scheduling
and off-line
will confirm
engineering
schedules
with
the
re-
(with the Inspacecraft op-
SSC,
the
example,
the
same
takes
if an observation
time
agree.
The
place,
the POCC
and
computer
commands
may
at
update
SSC will work
pass
to the
out a
goals
into
along
to the telescope
tion network. HST turn
The
position, on
the
certain going
commands,
Space
filter from
through
commands
open
an
Tele-
device
Most specific
spacecraft
to
and
operations
by software
embedded
a
on-board
computer.
In that case,
order the computer mands. will come
communication
to activate
The
POCC
surge
the
will
or switch
problem
can
be
telemetry data of the SSC and an be
will the
on-going data that
HST.
means
that
have
example
direct be
though
the POCC
The
Science
Support
objectives between
for
will pro-
other
organiza-
responsibility
would
even ble.
science conduit
that the POCC
support
for a task.
supporting
NASCOM,
is not directly
Center
will
responsi-
coordinate
with the STScl, acting as a the STOCC and the Institute.
with of
the
the
engineering
telescope
a science
Object
Camera
calibration
components.
schedule
If,
requires
for
the use of
STOCC may want to avoid filter wheels in the Faint
so jitter
spectrographic this conflict.
and
would
not
operation.
SOGS
would
affect
function
of the
the
resolve
data
instruments
One
the
SI
will be comin the
until
the
support
important
support
observers
analysis
manded
Telemetry
request
through
gyro
many cases, consultation
a spectrograph, the calibrations of the
the
or monitor
out
HST.
the voltage
background
example,
aperture,
the
Off-line
needs
them
may re-orient
setting,
detector
of the
repointing
mation
the communica-
detectors,
or grating
transmission C&DH.
pass
instrument
instrument's the
then
require
surge, and af-
The daily science schedule will pass through the SSC, and the STOCC will match the infor-
scope from the POCC, based on specific observation objectives. The POCC will translate those
a power
STScI, particularly if it affects observation. An example would
An
compromise. Some
In the
tions
is oper-
is scheduled
as a required
indicates
example, going to
a rate gyro assembly
to defuse
backup
vide
ated by the Institute and represents the astronomer's concerns, to balance the schedule. For
or the
sup-
that
which
disable
stability
solved. involve
processing,
will work
gyro assembly
could
Einstein
Explorer
sponsibilities: mission scheduling stitute), command management, erations,
which
of equipment
of the spacecraft. For can indicate that the voltage
the rate The
the status
HST's
the POCC the stored
will com-
of data
alert
the POCC
data
can
requiring gathered.
to that
need,
processed
example, the measurements
observer coming
see
when
a
being
be
to place
for
SSC
"quick-look" The
and the
will be to SSC
will
the incoming observer.
For
can look at preliminary from the photometer to
the
beam
into
a different
aperture. into
satellites
the
POCC
and provide
from
the
informa-
4-15
The Data
third
important
Capture
Facility.
part of the STOCC This
is where
is the the
data
will arrive
from NASCOM
The facility will reformat data from mission format, check for any noise mission
problems,
along
with
Support
and pass
a data
for
quality
the
Spaceflight (STDRN),
and
composed
Satellite
System
nications Ground Network
each
will
come
Data
(TDRSS),
the
of data
from
Relay
the
the
Network and Relay
NASA
Commu-
(NASCOM),
Spaceflight (GSTDN).
the transor trans-
packet
of the Tracking
Network
4.2.3.1
report.
STOCC
Tracking
handling.
for science
and
Tracking
and
the Data
Orbital
Hubble
mately
Space
330
maintain
an orbit
TDRSS
altitudes
into
noticeable
comes
deployment
orbit.
28.5- degree the Shuttle
angle launch
Kennedy
Space
relay
satellites
have
placed
two
falls
more
130 degrees
apart,
with a
ground terminal at White Sands, New Mexico. There will be a small "zone of exclusion" where the earth the
blocks
satellites,
will
be
TDRSS
the telescope
but up to 91%
within
receive
(science
mands
and
data)
and
engineering
The NASCOM
and
leases
orbit
coverage.
The
send
both
single(com-
The
from
domestic
the TDRSS
below
satellites
directly
such will to the
with
ground
stations
world-wide,
communications
the TDRSS.
communication data transmission.
eight
Unfortunately, time
is too
to the
limited
available
for lengthy
Characteristics
Three
major
affecting
Space
Telescope
factors
will be the orbital
will
its
arrays.
In that
atmosphere
at
orbit
to
altitude.
each
one
orbit
orbit
the
tele-
of the earth. a maximum
The of
of 28 minutes.
The
from
the
earth
the telescope,
the object
Space
shows
the
Telescope which
eight
blocks
the HST will have
as the
spacecraft
out of earth shadow. Faint-object be best when the HST is in the 4-13
itself
comes
viewing will earth shadow.
nominal
orbit.
orbit will be tracked
by the
will plot the spacecraft's
times
daily
Dynamics
Facility
future
in predicting
and
send
orbit
the data
at Goddard.
orbits, orbital
shadow
is If,
though
This
some
events is
at
to the will
inaccu-
such
as exit
expected
and
of the
characteris-
The
environmental
elements
tics for the spacecraft, its maneuvering characteristics, and the communications characteris-
impact on the HST orbit and other solar activities.
tics for sending and receiving data mands. These are discussed below.
upper
and
will
enough
complete
During
from earth unavoidable.
the success
solar
operating
an object,
to re-acquire
Flight
orbit
during a "nominal" 30-day period 34.5 and 36 minutes in shadow.
the object
least
at a
so that
the telescope's
to a minimum
viewing
TDRSS,
the
incline
plane
the faint
will pass into the shadow in shadow varies from
when
and
chosen
high
scope time
racy Operational
be
from
Telescope
36 minutes
--
will
on the
will
97 minutes.
help predict
4.2.3
atmopheric
play
every
The
supple-
where
The
will not decay
Space
operat-
nmi (368 kin)
orbital
directly orbit
the minimum
The
will
200
orbit
HST
drag
level
Figure
GSTDN,
provides ment
data
that
variation between
channels.
for commercial communications purposes, as television transmission. These satellites pass along STOCC.
of
HST's
multiple-access data)
system
to either
of the
communication
satellites
access
signal
the
approxi-
from the equator because will be due east from
Center.
put the sun in the
aerodynamic
communications
The
of
spacecraft
a minimum
above
to keep
orbit
will be The
between
--
light
will
km).
of approximately
drag
The
Telescope
nmi (607
ing altitude
addition, The
Characteristics.
com-
on
4-16
the
atmosphere
and
telescope,
thus
with
greatest
will be solar storms These "thicken" the
increase
the drag
accelerating
the
force orbit
Other
EARTH SHADOW
sources
affecting
zodiacal
light
starlight.
These
and
celestial
viewing
integrated
will affect
or
will be
background
the viewing
with cer-
TARGET
tain instruments, such as the light-intensity sitive High Speed Photometer. Solar-System SUN IN ORBIT EQUATORIAL LINE HST ORBIT PATH
objects
also
tioned
for
Object
Viewing.
will be affected celestial
Telescope
also must
work
parameters
for itself
and
and
decay
rate
4-13
HST
Nominal
considerably.
The
Orbit
Space
reason
Telescope
will be launched into a peak of high solar activity. This could affect the launch and orbit altitudes
required
by the
Space
Telescope
to com-
plete the first five years of the mission without falling below the 247-mi limit. If "worst-case" studies
hold,
reboost
the
the
the HST
mission
than
Space into
Shuttle
may
a higher
orbit
need
to
earlier
in
expected.
is because
comets.
tion
in orbit,
which
tion
toward
nearby
Solar
System
objects
scope
will need
object
toward to
Viewing. celestial
expose
10 hours, zone
The targets
if needed.
HST and north
and
by the
pointing
direcmost
that
the tele-
"snapshot"
of the
Tracking
inaccuracies
a blurred image observations
targets.
a
up
plane
on either of that
ZONE
1 _
.--.-.--
to
of the
side of the
orbital
celestial target
plane viewing remains
_
ORBIT
PLANE
earth. EQUATORIAL
Another
factor
celestial
targets
affecting
the
will be the
available for faint-object for an observation varies
year
and
the
HST
orbit
location plane.
of the
observation
amount
time time
the
if they of dim
viewing"
to the orbit
(see Figure 4-14). Otherwise, depends upon how long unblocked
for
A "continuous
"poles"
its posi-
orientation
detectors
up to 18 degrees south
a quick
the
However,
are so bright
are more likely to cause occur with long-exposure
NORTH ORBITAL
will be pointed
as a normal
will exist, parallel
the
Astronomers
geometric formula to decide period a target will be most HST is in shadow.
I\_..
of shadow
study. Shadow with the time of target, when visible
relative will
v, ING ,,,, ,e" zoNE-'----.---.._...,r._ _-' _,,/'/" _
a
in a given while the
Figure
4-14
.._.... _
"Continuous-Zone" Celestial
4-17
/
CONr,NUOUS I ,_""S'-'_//
to
use
PLANE
%.
of
as
off by it. The
CONTINUOUS
telescope
instrument
is changing
objects.
only
such
For example,
affects
to fix its position.
VIEWING
Celestial
HST
the
with imprecise objects
center may be try to lock onto
the
men-
In addition,
orbit
planets
System
by the factors
viewing.
position of Neptune's 21 km when the sensors Figure
Solar
Space
the outer
sen-
Viewing
_-
SOUTH ORBITAL POLE
The
Space
affect
Telescope's
the
view
maneuver the
that
30-degree
image
into
of rolls limit
attitude the
roll
object
the
may
and
require
spacecraft
(for
more
example,
a spectrographic
Lunar
also a
will
approaches
than
to place
Occultation
sensors
the
slit aperture).
within
moon.
But,
protect
the
ground
with
interior
planets
the HST will place
scope
opening's
To minimize telescope to block shadow rendering Venus.
the
falls on the of
how
i.e.,
HST. See the
HST
using after Figure
part
zone.
this exposure,
objects
sun;
which
the tele-
for a
uously
observe
netic galactic
team
of the
the
could
bright
use
that
servos,
the
the moon
for an observation.
be
HST
controls
selector
The
as an moon
between its "new-moon" phase so the occulting
moon
precedes
(see
Figure
Radiation. Energetic sources will bombard as it travels
shielding
4-15
Observing
4-18
Venus
around
will block
component
SUN SETS
Figure
star
is in shadow,
Natural different
sunset
4-15
would
degrees
the
the
and edge,
illuminated
4-16).
the
the earth the
ten
fine guidance
when
overriding
object
of the
The
away"
sensor
likely would "quarter-moon"
Venus)
sun-exclusion from
will view these
and
the sun within
50-degree
the danger
(occult)
(Mercury
by
control
occulting Tracking
Viewing.
"look
of
the
particles from the HST continearth.
much particle
Geomag-
of the solar "radiation."
and
periods. Careful scheduling will minimize the effect of the SAA on the mission, but it will have
RELATIVE MOTION OF
Z?2
some
regular
Solar
flares
impact.
are strong
accompanied The
MOON HST FOV
by bursts
earth's
magnetic
pulses field
regions,
inclination,
from
most
ticles.
flares
are
The
radiation,
of energetic
magnetic
latitude
of solar
particles.
shields
the
lower
such as the HST orbit of
these
charged
monitored
par-
regularly
by
NASA, and the HST could stop an observation until the flares subsided. The greatest physical GUIDE STARS ECLIPSED TARGET
J
AFTER
Figure
the Space
South
Atlantic
Using the Moon Occulting Disk Telescope
Anomaly
magnetic
enter
the
detectors, false data.
telescope
charged
and
emitting
strike
through
the
verification,
measure
the
instrument significant, cameras
effect
in the
will move
could
at
a
the
photon-counting
probably passes by
will not through
this
the
ability
Nonetheless,
the
may
hold precise
The
stars
trates
to
the
lock
used SAA.
onto
spectrographs if the
or the rate
on are
in the
when The
occasionally
in
the
Telescope
minutes
One
danger
guide
stars.
the
photome-
guidance
sensors
gyros
can produce
sky must
tion,
can a
direct
there
portions affected
the
or
4-17
illus-
it will take a new
a few
target
This means
be
scanned
and
a larger for
guide
the
is some of
solar
radiation the
thermally.
array
concern aft
long.
out of In addi-
that
unprotected
shroud
could
Therefore,
beyond
wings
for too
SSM
will be the
there
a certain
are
range
be limits
in angle
the SAA
scope
with
Figure
with maneuvering
of moving
sun's
encounter will last up to 25 minutes. the SAA rotates with the earth, so it earth-shadow
to move
degrees/sec
and lock onto
consideration
When
will coincide
by
maneuver.
drift errors.
of the
noise
or nine consecutive orbits, with it for six or seven or-
enters
pitch
to track
region stars.
0.22
maneuvers,
will accumulate
could
will pass through
in space
It will be able of
14 minutes.
HST
to maneuvers and time.
for segments of eight then have no contact bits. Each In addition,
rate
a roll and
also and
Space
the
image.
Space
spacecraft
devices be
bombardment
be usable
guide
radiation
that the effects
The
its orientation
the spacecraft.
baseline
90 degrees
producing
will run tests to
particle
If it appears
produced
ters
of
data.
spacecraft affect
the Institute
will change
a "hole"
and
Characteristics.
rotating its reaction wheels, then slowing them; the momentum change caused by the reaction
particles
the instruments'
electrons
Maneuver
Telescope
passes (SAA),
field,
4.2.3.2
as an
When During
activity, subsided.
DETECTORS
4-16
When earth's
danger would be crew extravehicular which would be halted until the flares
HSP
HST
as the
observation
the
the HST performs 50
a pitch
sun-avoidance
will curve
away
from
ple,
if two
targets
are
just
outside
the
50-degree
follow
4-19
degree
an imaginary
the sun.
opposed
circle
to a target zone,
zone,
the
near tele-
For exam-
at 180 degrees the
of 50 degrees
HST
will
around
general
orbital
supplemented Network
Control
schedules SUN
week.
to be filled TARGET
Center
Most
schedule,
science
requests.
will prepare
15 days before
mission
(a) Vl (ROLL) MANEUVER
communication
by specific
the beginning
HST
requests
with no conflicting
The
advance of each
are expected
TDRSS
requests
1
(VIEWING AWAY FROM SUN)
(b) V2 (PITCH) MANEUVERS (MANEUVER PLANE CONTAINS SUN)
Figure
4-17
HST
Singe-Axis
50°
/
Maneuvers 50*
the
sun
Figure
until
it locates
the
second
(see
/
l
4-18).
4.2.3.3 Communication HST will communicate Tracking
and
(TDRSS). 130 degrees
Data With apart
amount of 94.5 minutes
Characteristics. with the ground Relay
two satellites in longitude, the
contact time of continuous
The via the System
TARGET2
placed maximum
Figure
Satellite
will be up communication,
with only from 2.5 to seven minutes of exclusion," out of reach of either Figure
target
PATH OF HST SLEW
/
J
(FACING SUN BUT ANGLED 50* AWAY FROM DIRECT CONTACT)
j
4-I8
Sun-Avoidance
Maneuver
to TDRS EAST long. 41 ° W
TDRS WEST long. 171 ° W
in a "zone TDRS (see
4-19).
However, orbital communications situation
variations by the satellites will affect
to widen
the zone
HST and this ideal
of exclusion
slightly. soRs WEST s.Aoow _.s,_!o
The Goddard Control Center munication.
The
Space Flight will schedule Space
Center Network all TDRSS com-
Telescope
will
have
COVERAG)EAST SHAOOW ZO_ ZONE
a
4-20
Figure
4-19
TDRS-HST
Contact
Zones
from other spacecraft,at leastin the early part of the mission.
2.
The
ing data, nas
cannot
single
GSTDN
or science transmit
contact
factor
In practical
system
tacts
would
be
existing
at least
required
between
GSTDN
to read
data
gaps
track
Each
the communication
fine-pointing
in that
antennas
coverage
multiple-access
from
a
continuunneces-
even
will provide
via
TDRSS
command
phase
operations first
can during
at least
for rate
of the
Space
is maintenance spacecraft
in orbit.
Normal
the
95%
NASA
currently
upgraded
is developing
mission
the
science
instruments
to
objectives.
The decision-making and operational responsibility for HST maintenance, when that is required,
currently
Flight
Center
Space
Flight
lies
with
(MSFC). Center
Marshall
Eventually
(GSFC)
Figure
involved in deciding a mission.
a
Shuttle
4-20
Space Goddard
will assume shows
whether
minimum
maintenance
the
that
process
or not to schedule
Telescope.
their
in orbit.
designed
will has been
would
(MMs),
five
years,
Days
is in Figure
The Space
Shuttle
Replaceable
Unit
with
for
A mission seven
days,
activity 3 and
5. The
(EVA) generic
4-21.
-- Some
will carry Carriers
replacement
exchanged
to be replaced
in orbit
for Flight
the HST is
bay.
be scheduled
the
will perform
while
extra-vehicular
timeline
recapture
crew
payload
Space
is
maintenance
of equipment
need
HST
missions
as the nickel-hydrogen
a five-year
The
every reasons:
degradation
the HST
for
mission
the
assignments
in the Orbiter the
the
with and
Then,
maintenance
berthed
MM
mission,
will rendezvous
Space
used.
Telescope
Maintenance
equipment such
providing
extend
with
scheduled approximately would occur for several .
so
if the main
is impaired.
scientific
scheduled
while
capabilities, even
second-generation
currently
the
system advances
responsibility.
MAINTENANCE
Another
redundant
the
has been
maneuvers.
The low-gain
4.3
to replace
Telescope
equipment advances in technology may justify replacing operating equipment. For
During
orbital
communication maintenance
necessary Space
if a unit's
con-
antenna
satellite,
--
of the mission,
can function
Technology
example,
recorder -- with gaps of up to transmissions.
in communication.
with
systems
unit 3.
contacts
Each high-gain antenna will maintain ous contact with one TDRS to avoid sary
most
be The
designed
will be
three
may
equipment.
longest
of this backup
terms,
filled science tape 11 hours between
The minutes.
the large gap in time with the HST.
mission
anten-
will be eight
failure
continuation
such as loss of power or capabilities, an unscheduled
engineer-
if the high-gain
to TDRSS.
time
The limiting
will receive
data
equipment
loss endangers
The backup communication link will be the Ground Spacecraft"l)'acking and Data Network (GSTDN).
Random
(called
up to two Orbital (ORUC)
units
that
changeout)
units
during
the EVA
period.
The
following
typical
example
packages would
be
with the
existing
outlines
the pro-
after
for several
years
batteries,
with
lifespan.
cedures during
4-21
for
replacement
a maintenance
of a selected mission.
ORU
HST RETURN
I NO
M R sou cE F-[ UNSCHEDULED
SYSTEM PERFORMANCE
FAILURE
DATA
EXISTS
_"_'- [
AVAILABILITY
OF H
MAINTENANCE
SAFE
HST
POSSIBLE
LOSS
• ORUs
MODE AUTONOMOUS
H
MISSION
• SSE
ESTABLISHED
• STS
_NO
NO HST
FLIGHT
__S
DELAY
YES
IMPACT ASSESSMENTS
SCHEDULED
I
OSS
OF
M&R
SCIENCE
MISSION
RESOURCES AVAILABILITY
4""o! ! I J
TO
NEXT
MAINTENANCE
NO
I I I I •
CONTINUE
•
• ORUs
MISSION
• SSE
WARRANTED
DEGRADATION
• STS
UNSCHEDULED
LOSS
REDUND-
•
ANCY
(MISSION
MISSION CRITICAL
ETC ESTABLISH
FUNCTION
MISSION
MONITORING
! I I I
i I I I
SAFE MODE POSS,BLE CONT,NUEDEGRADED
NO
NO
--
HST
TO
DELAY
NEXT
SCHEDULED
FAILURE •
PARTIAL
•
LOSS NON-CRITICAL
HST
DATA
MISSION
RETURN
ORBITAL
PARAMETERS
t tN°
ESTABLISH
YES
REBOOST AVAILABILITY
REQUIRED
I
SOLAR
DATA
t
HST
M&R RESOURCES • STS
REBOOST
MISSION
_
NO
SAFE DELAY
MODE TO
POSSIBLE NEXT
MISSION " SCHEDULED CONTINUE DEGRADED HST RETURN
Figure 4.3.1
Maintenance
4-20
MM
Call-Up
Scenario
Trip Decision 3.
The
Process
Orbiter
will match
minimizing will launch
The Shuttle
and
Space Telescope on the retrieve it as follows:
rendezvous
second
with the
flight
day,
and
4.
thruster A crew
propulsions. member will
manipulator ple onto
1.
The STOCC stability,
high-gain
will report
and
the HST attitude,
whether
antennas
the
are
arrays
extended
and
or
retracted. 2.
The STOCC scope and
the aperture
the Space
system the
HST
control
(RMS) forward
maneuvering
the
berth
Flight
RMS
will
Support
the
Structure
on the base
orbit,
of the HST from
The astronaut
the camera will command
to stow the antennas close
5.
the telescope
contamination
the arm
and
remote grap-
shell.
the HST with telescope (FSS),
on
the
guided
by
of the FSS platform.
Tele-
and solar arrays
door.
4-22
When the Space Telescope the crew can tilt or rotate
is latched to the FSS, the berthed HST (see
CREW ACTMTY
nicate
DAYS
with the
RMS FLIGHT
DAY 1
Launch/On-Orbit Preparation
FLIGHT
DAY 2
Rendezvous/Retrieval
FLIGHT
DAY 3
EVA #1
FLIGHT
DAY 4
HST Reboost/Crew
Rest
arm
crew
from
inside
member
for
STOCC
through
After
leaving
their
personal
cable
that
member
the Orbiter
the
EV1
safety
wrist
along
each
protects
the
FLIGHT
DAY 6
HST Checkout/
floating
Redeployment
the
De-orbit/Landing
EVA equipment to gather tethers, two tool caddies,
FLIGHT
DAY 7
cargo
while, Figure
4-21
Figure
Maintenance
4-22).
During
vertical relative each EVA the position
and
the
Mission EVA
to the Orbiter HST is tilted
latched
to the
Timeline
the
HST
restraint
will be
cargo bay. After to a 32.5-degree ORU
EV2
(MFR)
Finally
EV2
safety
left wrist handrail.
climbs
assembly
tether
covering the
containing
manipulator
installs
it into
onto
the
to a D-ring
thermal
Figure Two crew
4-22
HST
members,
from
--
Z _oo
In Position
designated
on FSS EV1
is the ORUs
a portable
foot
and
EV2,
crew member on the HST, restraint
(PFR)
that can be placed
in receptacles
throughout
HST. from
crew member manipulator
who, working foot restraint,
EV2 the
removes passing
is the RMS and
them
to six hours On Flight through them
to EV1. of EVA
ORUs The
Orbiter
the Orbiter
on
EVA
the crew
in a 24-hour
Day 3 the EVA the
into
installs
the
RMS
MFR,
attaching
on the
EVA
suit
tethered
the
System
Bay
1 to assist
Module
out,
the
(SSM)
a tether
releases
computer
on
to the DF-224,
port
replacement removes the
attaches then
oper-
the
moves
to
the
six
ORUC.
to the Sup-
equipment
section
0
will suit up for EVA. EV1 who removes and installs working
L
blanket, DF-224,
holding
EV2, ---
foot
bay, with the IV crewmember
replacement
J-hooks
x:951
to
a miniworkstation, and a PFR. Mean-
ating the RMS. EV2 moves to the DF-224, mounted on the ORUC,
x=a92.o
from
moves
and a second safety tether to the RMS Now EV2 moves to the ORU carrier
in the cargo
ORUC
cargo
members
bay. EV1
the RMS
and
attach
grapple fixture, then configures the MFR with tool boards and portable lights and handles. one
carrier.
stowage
unstows
the
to a tethering
crew
in the cargo
bay
EV2
of the Orbiter
EVA #2
off once
the IV
with
and
tethers
DAY 5
sills and
and
IV crewmember.
the airlock,
runs
the
(called
intra-vehicular),
FLIGHT
bay
maneuvering
cargo
ORUC, is limited
period.
crew prepares
airlock,
the
which bay. They
to pass will
take
commu-
4-23
EV1
DF-224
inserts
guiderail steps
EV1
PFR
below
the
in place.
EV1
releases
the door
closed,
then
which EV1
in Receptacle
into the restraint
for STOCC
approval
door
the opens
disconnects
seven
releases
the six J-hooks
er, then
pulls
the
location
and
transfers
EV2
tethers
1, then
the suit's
six J-hooks the door.
to disconnect
is communicated
27, on the
to Bay
and locks
through wing-tab
the side of the DF-224 heater connectors. EV1
EV2.
or changing
computer.
the
just
in replacing,
boots
holding EV1 waits
the DF-224, the
IV:. Then
connectors
at
and the two wing-tab tethers to the DF-224, to remove
computer the
to the
from original original
the computits mounting DF-224 DF-224
to and
transfers Then
the EV2
replacement
takes
the
DF-224
original
to
DF-224
ORUC and installs it where unit was stowed. Meanwhile,
the EV1
EV1. to the
replacement has tethered 32.5
and
positioned
Bay
1.
the
replacement
DF-224
/
O___
in
FSS
Now EV1 engages J-hooks, attaches
and torques the connectors
tight the six to the new
I
unit, and informs the IV crewmember that the DF-224 is installed. EV1 closes the Bay 1 door, re-engages stows the and
the J-hooks and tools on suit tethers,
removes
it from
tightens them, exits the PFR,
Receptacle
Figure
27.
the cargo altitude
This operation
takes
approximately
two days
pattern,
of EV
activity
stowing earth. The
the
decision
for
charging/discharging of the
of replaced
Space
can
reboost
This EVA1
the Space
return
With
the
the
4-24). alti-
tude, and upon completion of the planned maintenance activities, the crew deploys
crew the
Shuttle
reaches
Telescope
original
in the
the
same
new
manner
as
the
deployment.
to
will
MISSION
The
Hubble
OBSERVATIONS Space
specific targets the observational
Telescope
will
study
in the sky in its lifetime. work will be highly
many
Much of technical
and very specific, such as estimating the ratio of helium to hydrogen in quasi-stellar objects
degreda-
the HST, then and its comple-
spacecraft on
the
has decayed to a higher
flight
be-
the Shuttle day
orbit. between
EVA2.
the
to a higher
maintenance
altitude,
//
For this operation, the Space latched to the ORUC keel 4-23).
Figure
will move
Telescope
orbit
acceptable
is scheduled and
(see the
Space
capacity.
two-day
Telescope's
low a minimum
bay, the Orbiter
Position
units.
Reboosting
If the
to-
to replace
upon
mission, the crew will redeploy return to earth with the ORCU
4.3.2
the
units
depending
completion
ment
working
upon the status of the HST flight configFor example, the batteries may or may
of their
After
unit
on which
not be replaced, tion
this general
the units to be replaced, the replacement unit and
removed
in Reboost
orbit
4.4
final
depend uration.
follow
with the two crew members
gether, one removing the other retrieving
HST
55 minutes. When
The
4-23
I
HST
latched
Telescope latch (see to the
will be Figure
ORUC
in
4-24
,
.
__(:,.?.
Figure
4-24
..... ,.... Shuttle
4.. Reboosting
..... the HST
(quasars)
to evaluate
the age of the quasar.
general observational Telescope include:
goals
set
for
the
But Space
Both mission examples are based on studies the Hubble Space Telescope project team. 4.4.1
•
Measuring
the
distance
thest away from standards to use distances •
how
chemical gaseous
us, and developing better in measuring the immense
stars
of stars,
clear explosions a star's life. Searching
that
planets
the most and
that astronomers 90% of the bulk
of
Section
these
distant
early
such
of each
there
vations
Sys-
development
of the
existence of matter and invisible matter
are
in
4.4.1.1
(see
of the
aperture
there
the Space
the Hubble
it is impossible
that represents Space
Telescope
all obserwill make.
Nonetheless, the following section approach two "typical" observations.
will
with
parallel
Planetary opportunity" by the Goddard
observation
by the
Wide
Camera,
and
study
of an exploding
High
Resolution
a
of
4-25).
The
different
will make
Telescope
Each
position
precise
pointing
To
must
a
to make HST can
increase
the the
18 minutes
stars.
If the HST
fixed-head
star
over-
trackers
coarse-pointing updates use the FGS again.
probability HST
of multiple
the
plus the time the FGSs
the guide the
center
to reposition
-- an estimated
its target,
may have before the
the FGS
90 degrees,
to acquire
shoots
flight
of
a
software
guide-star
pairs
successful allows
the
to account
for
any natural contingencies guidestar acquisition --
that might affect a such as a guide star
being
preventing
a binary
star
and
a "fine
lock"
from
getting
fore,
an observer
cludes
selection
proves
and
studying
tion process takes switches to coarse tion
to acquire
the
that inpairs.
to acquire,
to the alternate has a limited
FGSs There-
a proposal of guide-star
too difficult
sors can switch each observation
the
on the target.
can submit
a multiple
one pair
quiring The two observations selected are the study the Vela pulsar by the High Speed Photometer,
Observation.
is the time it will take
to maneuver
use
observation,
observation, and data
has an entrance aperture, portions of the HST focal
sizes in which
target,
observa-
an example
observation
sometimes-lengthy procedure for the fine guidance sensors (FGSs). In addition to the small
will present
in the steps
Figure
apertures
section
variables
in the
and
scientific instrument all located in different
acquisition,
are so many
required
Acquisition
scientific process
steps
analysis.
to specific the
Procedure
process are target acquisition and data collection and transmission,
take as
discussed
major
relate
individual
to present
Solar
for clues
tion examples to demonstrate involved in an observation.
Because
as black galaxies,
in our
The
plane
mysteri-
objects
observations
This
of
think makes up as much of the universe.
3 as they
instruments.
beginning
exploding
universe, including the before galaxies formed,
Many
the
the nu-
on many
pulsars,
origin
the
universe,
the outer
Examining to the
and observing signal
in the
quasars,
and even tem. •
by examining
for information
objects
holes,
form,
Observation
far-
composition of existing stars and of nebulae, which astronomers feel are
the birthplace
ous
objects
in space.
Studying
•
to the
by
If
the sen-
pair. However, total time for ac-
target.
If the
acquisi-
too long, the acquisition logic track mode for that observa-
the
guide
stars.
Field/
"target-of-
There
are three
supernova
target
a star.
Spectrograph.
transmit
4-25
basic Mode
a camera
modes
that will be used
1 will point image,
the
HST,
or spectrographic
to
then or
FINE GUIDANCE HIGH
SENSORS
+v34
RESOLUTION
OPTICAL CONTROL SENSORS
(3)
PEED PHOTOME TE R
FGS #2
r.-_
II
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I I
\ HSP
k\
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__
14.1
AXIS
arcmin
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FAINT OBJECT CAME RA
2 DETECTORS, SE PARATE APERTURES
4.4.1.2 Data Analysis. Once observations begin, SOGS will schedule the expected data transmission from the tape recorders, usually within a few hours of collecting the data. Status information will be readied so it can accompany the data. Data will pass from the observing instrument to the SI C&DH, where the science data formatter will convert the data into trans-
pass along the data packets to the White Sands ground terminal, which will transmit the information to NASCOM. The science data will go to the Data Capture Facility (DCF) via a NAS-
X
FAINT OBJECT SPECTROGRAPH
COM
INCOMING IMAGE (VIEW LOOKING FORWARD +Vl AXIS INTO PAGE)
HST Instrument
satellite,
for processing will receive transmitted.
WIDE FIELD/PLANETARY CAMERA
Figure 4-25
to
mittable packets. From the SI C&DH the data will pass to the high-gain antennas, which will beam the data to the TDRS. The TDRS will
! FOC
Section 2.3.1 details how the FGSs operate lock onto a guide star.
then
from
the DCF
(see Figure engineering
to the STScI
4-26). The POCC data when it is
If the Space Telescope moves out of communication with the TDRS, the collected data will go onto a Space Telescope science tape recorder for later transmission.
Apertures
photometric pseudo-image, to the STOCC. Ground computers can make pointing corrections to precisely point the HST, and the coordinates will be passed up through the DF-224 computer. Mode 2 will use the on-board facilities, processing the information coming from the larger target apertures, then aiming the HST to place the light in the chosen apertures. Mode 3 will use the programmed target coordinates in the Star Catalog or updated acquisition information to re-acquire a previous target. This is called "blind pointing" and probably will be mostly for generalized pointing and for the Wide Field/Planetary Camera, which does not require such precise pointing. Mode 3 likelywill rely increasingly on the updated guide-star information from previous acquisition attempts, stored in the computer system.
4-26
Incoming data will go into SOGS, where the data base management converts the data into SOGS format before storing the updates in the Science Institute archive. The SOGS software will examine the data for duplication and missing or bad portions of data. Bad data can be DATA
II
s,
I_
/ORS
_.
STOCC
, ST SCI
Figure 4-26
Data Transmission
Pathway
retransmitted recorders. SOGS
if
will edit
it
is
the
stored
usable
on
data;
will go into
a separate
file
and salvage,
if possible.
SOGS
used
neering
can compare
data
packets
verify
engineering
observing
instrument
flooded data.
the
data
diodes
and
editing
step
example,
software
will
wavelength
measurements
stroms
remove
and
grating
Speed Photometer the HST is in
eight-hour period. Camera will make to provide region
useless
any
and
in the STScl
checked, archives
more
precise
The
Vela
writers,
and
other
output
Observation
There
are
below
are
many
data or
can
of expected operations selected observations.
that
involved
Vela
Pulsar
study
drives,
to point
toward pulsar.
the pulsations.
magnitude
of 24,,. The
pulsar
is scheduled
The Vela pulsar observation
over several
45
1), communicating The of
coarse the
general
celestial
the pulsar
is
the observacquisition
through
targeting
region
degrees
HST will begin
Because
the
TDRS
will be based
taken
earlier
The
pointing
stars
that will place
system
will search
on
by
apertures.
or
tion, and the change provides needed for the slew. It will take
film
assemblies
the
maneuver
position.
Then
while
the
FOV
to a maximum
sensors
FGSs
the
guide pul-
speed
to settle
HST
into
remains
out
angle
of rota-
the momentum a few minutes to
and the
for the
the
the Vela
The HST reaction their
spiral-scan
search
for
the light from change
from
the
of 90-arcsec
guide
stars.
finally
are
the
stable FGS as the
type
HST's
Vela
has a
of the Vela
different
the
wheel
pulsar is a subject of great interest, because astronomers theorize that a neutron star may be producing
The
such a faint object, the STOCC and er will direct the overall target
Once
the
Space The
about
equator.
sar into the correct
planned; up the
in the
Observation.
to assist
WF/PC.
is located
of the Vela
times,
4-27
guide
stars
Telescope
observe 4.4.2.1
for the
pulsar
complete
being point
pulsar
photograph
be
sources.
observations
The
the
could
Examples
two examples
study
the spectrograph has a and pointing must be
region
new 4.4.2
in the Vela
Spectrograph. to
slewing
images WF/PC.
data
tape
than
the celestial
(Mode
errors,
for future
use, or it can be sent to printers,
Object
scheduled
in target pointing, since much smaller aperture
from
that
the
of the stars
can use the camera's
satellite.
Calibrated software
The Wide Field/Planetary a parallel observation, partly
for the Faint
to ang-
coming
problems
indicate faulty transmission, instrument troubles. calibrated
spectrograph pixels
signals
movements. for
This
data into scientific signatures. For from
to observe the pulsar earth shadow, over an
a photograph
spectrograph,
the pulfor the
that
the data.
convert
noise
carrousel
be checked
stored
that the
produced
will calibrate
step will convert telemetered form and remove instrument
Once
For
a malfunction
High while
later,
engineering
observation.
since various instruments will examine sar. The scheduled observation calls
below
A final
will
engi-
astrono-
may indicate
had
blank into a
and
so the and
the
data
with data
science
the science
to
data
will edit the data
This will be done
mers
example,
unusable
data the
for all incoming
data.
tape
for troubleshooting
by filling gaps from missing "fillers." Then it will reformat format
HST
the
scientific
pulsar.
targeted,
instruments
The
ground
the can
computers
already will have taken the camera image and computed the coordinates for the center of the pulsar. the place
These
telescope the
coordinates
as small-angle
target
HST will move
will be transmitted
into very
the
slightly,
slews HSP
needed
aperture.
measured
to to The
in a few
arcsecs.Each maneuver the total
less than three
sar
onto
light
satellite
the
will take minutes
HSP
is in position,
seconds,
to lock the pul-
aperture.
If the
the photometer
out
TDRS
immedi-
ately will begin sending light-intensity camera will send its data in one burst passes
with
data. The as the HST
of the shadow.
selected
for that
munication because
of other
50 minutes
of waiting
earth
shadow
from
the
mission
(see
Vein
path
as the Figure
pulsar
already
HST passes 4-27).
will
eight and out of
Information
follow
the
trans-
described.
may
only a few days to peak, time
to prepare
consulting
image
as
(see
Institute
an
the
rendering
will
study
4-27
HST
4.4.2.2
Supernova.
expects
targets
celestial
events,
the mission. opportune
Passes
of
Science
opportunity,
to occur
The chances target
Out of Shadow
The
are good
Institute the life of
that one such
will be a recently-discovered
supernova. The
process
pected vation. different
source The
of trackingand is different
pointing from
there
charts
and
supernova bright
in Figure
the
mission a
by star
4-28).
schedule,
limits to select newly-detected
software
will search
a for
the time exposures results from the cho-
camera
information
will
to be converted sent to the HST.
Mode
will be used.
1 acquisition
probably
the HST already shot,
the target
guide
will lock
onto
supernova
will be coarsely it will slew until
star. Then the
guide
the guidance stars.
will pass into a targeting
calculations
to adjust
data
aperture.
data
will come
Data
Capture
Light
moments
sensors from
aperture
the light precisely
A few from
pointed it captures
later
the new supernova
the for
into the the
first
into the
Facility.
at an unex-
a planned
HST may be pointing
direction,
GSSS
for the camera
unscheduled
throughout
STScI
TDRSS
produce a set of coordinates into maneuvering commands
Since Figure
The
direction.
The
extremely
guide stars, then calculate required for the best data sen instrument.
The
any current will take a
is analyzed
astronomers.
appear
supernova. SHA
with the
emergency
the camera
orbital path, and instrument favorable observation of
EARTH
be
supernova agree
in the proper
will request
while
exploding
The
must
to reschedule the STOCC
the camera
STOCC
support, might
would
information.
image of the supernova sky area with Field Camera, after the HST maneu-
vers to point
the
so there
an unexpected
director
observing astronomer observations. Then
The
unavailable A supernova
targeting
make
the STScI
"finding" the Wide
be
commitments.
little
sighting, over the next of data collection
of the sky, and the com-
takes
If astronomers
This cycle will continue hours: about 40 minutes
region
satellites
obser-
in an entirely
may be no guide
stars
4-28
The
data
accumulated
into SOGS manner.
and
be
on the supernova processed
in the
will go regular
Figure
4-28
WF/PC
4-29
Image
of a Nova
Section HUBBLE Managing
the Hubble
project is a team participants. The National tute
(LMSC),
(P-E),
and
(IDIs)
and
and/or built struments.
The
Space
Missiles
instrument
the
satellite
Telescope
Administra-
Telescope
interlocking
in the
deployment,
and
Space
Telescope
Space
AL, is the project
development that
Telescope's
5.1.1
NASA
Flight
ter. MSFC
teams designed
scientific
in-
ment
deployment, scope. seeing
launch of
charted
members
the
and
Hubble
in Fig. 5-1.
charged
Space
Telescope
period
HST. MSFC
is responsible
involved
in the
5.1.1.3
Goddard
dard
will
working
many offices and centers sharing for the development, launch and and operation
of the
Space
Tele-
from overaspects of
ground
are
detailed
with
Headquarters.
the
(AD). A maintains administers
entire
for the director
The
space
science
Orbital
deploys
for meeting
the
the cost, goals of the HST elements
Space
oversee
the
very closely developed
Flight
Center.
Scientific
with
Verification,
the Science
by Goddard,
God-
Institute
the STScl,
P-E,
Johnson
Space
Center
sible
Telescope
of the
Astrophysics
project
for
Orbiter
Once with
See the
Center.
in Houston, Shuttle
The
Johnson
TX, is respon-
Orbiter
flight opera-
HST project, JSC's responsibilities all interface requirements between and the
Space
Telescope
payload.
training for specific such as maintenance
operation.
launched, the
Center
lies
Control
Division
the
Space
(JSC),
for the Space
tion. In the also include
The
program manager for the proiect, and
resources
of the spacecraft. information about
NASA
program.
Space
Space Telescope policies and goals NASA
the
after the Shuttle
JSC also oversees crew HST support maneuvers,
below.
of Space Science and Applications in Washington, D.C., plans and directs
authority
the develop-
and
project.
or contingency
the agency's
with
cen-
system.
5.1.1.4
the
Office (OSSA),
(lead)
and Lockheed. Through the Space Telescope ground system, Goddard will control the
Responsibilities
NASA
in Hunts-
management
Verification
on tests
the project to specific responsibility for a single function, such as launching the Shuttle with the HST aboard.
5.1.1.1
(MSFC),
Mar-
of the Hubble team
operation
responsibilities
Center.
schedule, and technical performance the Space Telescope. It also manages cost and schedule of the other
These responsibilities range the financial and management
NASA
Flight
has been
of the
scientist
policy.
Center
day-to-day operations Chapter 4 for more NASA has responsibility
HST program
Space
shall
development,
are
Marshall
ville,
Corporation
management
participating
5.1.1.2
The science
Com-
responsibilities
Telescope
overall
& Space
RESPONSIBILITIES
Space
program.
oversees
Insti-
subcontractors
the Space
MANAGEMENT
Science
Perkin-Elmer
the
PROGRAM
Telescope
and
Lockheed
pany
TELESCOPE
of government and private primary members are the
the Space
(STSci),
5.1
Space
Aeronautics
tion (NASA),
SPACE
5
Space
5-1
cific crew, crew Control
the
Space (STOCC) Center.
Orbiter
Orbiter
Telescope through
Control
Johnson's
Mission
JSC will be responsible flight
and interacting manipulates Center
will communicate Operations
will
operations
for spe-
involving
the
with STOCC when the the HST. The Mission perform
Orbiter
flight
NASA
HQ
I SPACE FLIGHT MARSHALL CENTER
1 MISSILES & LOCKHEED SPACE CO.
--
--
m
HST SYSTEMS ENGINEERING INTEGRATION
_
&
HST/ORBITER/CREW INTERFACE & OPERATIONS
SOLARARRAY FAINT OBJECT CAMERA
HST ASSY & VERIFICATION
SPACE FLIGHT GODDARD CENTER
ELMER PERKIN
HST LAUNCH & ORBIT VERIFICATION
--
--
SIC&DH SUBSYSTEM
FGS SYSTEM ENGINEERING
SUBCONTRACTOR MGMT
5-1
on
the deployment and reboost flights.
Space
Kennedy Center,
launch
site
responsible placing
Space at Cape
for Shuttle
--
HST MISSION OPERATIONS
p
TDRSS
Space
flight
Telescope
and
on
most
Office
Data NASA
project
Canaveral, flights.
Telescope
NASA
FL,
is the
Kennedy activities,
also
is
such as
in the Orbiter
Facilities.
The
will rely on the Tracking
Relay Satellite commercial
SUPERVISION OF SCIENCE OPERATIONS
--
SCIENCE& ENGR DATA ANALYSIS
--
ASTRONOMICAL
HST/ORBITER LAUNCH VERIFICATION
of Space these
car-
5.1.2 The
Space major
scope science
System
satellites
communication.
Tracking
and Data
Systems
operations.
(TRDSS) (NASCOM)
Space
Telescope
Institute
of the
Institute are to and coordinate
operations
ground
Science
responsibilities
Science program
Institute's Telescope
--
FINDINGS
ground-to-spacecraft
scope Other
I
SCIENCE OPERATIONS PLANNING
Kennedy
go bay.
5.1.1.6
I
SPACE CENTER
--
Responsibilities
The
Center.
for the prelaunch
the Space
KENNEDY
II |
_LAUNCH
manages 5.1.1.5
I
HST OPERATIONS CONTROL CENTER & SCIENCE OPERATIONS FACILITY
Figure operations maintenance
SCIENTIFIC INSTRUMENTS
FAB, ASSY & VERIFICATION OTA DESIGN,
OPS
I
TELESCOPE
SCIENCE INSTITUTE
I
HST IN-FLIGHT MAINTENANCE PLANNING
HST MISSION PLANNING --
SPACE SPACE JOHNSON CENTER
SSM DESIGN, FAB, ASSY & VERIFICATION
I --
I
SPACE EUROPEAN AGENCY
I
]
counterpart
with
the
in the
Space
Tele-
manage Space
the Tele-
STOCC, Space
the
Telescope
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and
and
The
science
for
the
HST
5-2
program observations,
involves selecting
setting the
goals
for
observa-
using SPACE FLIGHT MARSHALL CENTER
I
I
TELESCOPE PROJECT HUBBLE SPACE OFFICE
MODULE SUPPORT PROJECT SYSTEMS OFFICE
ENGINEERING SYSTEMS OFFICE
l
t t I
!
to
and
analyze
make
Institute
has
participated
in the
prepara-
tion of the scientific instruments, development of the instruments
assisting in the from an astro-
nomical tests.
of verification
basis,
and in the creation
5.1.3
Lockheed
Lockheed
PROJECT CHIEF ENGINEER
Missiles
in Sunnyvale, LMSC
I !
vised LMSC
is the
contractor
Support
co-prime
work
contract
fabrication
Company
of the
is the the
and
MAINTENANCE AND REFURBISHMENT OFFICE
• HST DEVELOPMENT
& Space
& Space
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development PROGRAM PLANNING AND _ROL OFFICE
Missiles
of many includes
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Systems
contractor
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PROJECTS OFFICE FLIGHT
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OFFICE FOR HUBSLE FLIGHT TELESCOPE PROJECTS SPACE
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• TOTAL PROJECT MANAGEMENT • OTA DEVELOPMENT
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SSM DEVELOPMENT HST INTEGRATION AND VERIFICATION ORBITAL VERIFICATION OPERATIONS MAINTENANCE AND REFURBISHMENT
Figure
5-2
plans
that
interweaving
MSFC Space Organization best
cohesive and interactive the science operations and processing craft's scientific
Telescope
accomplish
all the selected
PLANNING
EXPERIMENT SYSTEMS OFFICE
those
goals,
observations
into a
schedule, conducting through the STOCC,
the data produced instruments.
]
GROUND SYSTEMS AND OPERATIONS OFRICE
t I I
SYSTEMS ENGINEERING OFFICE
RESOURCES MANAGEMENT OFF_ED
by the spaceGSFC RESPONSIBILITIES
Time
management
Institute,
because
vation
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have
handle
will
be
it already than
produced guaranteed
this management
important
to
has far more
obser-
it can fill. In addition, the
scientific
the
• • • • •
SCIENCE INSTRUMENTS DEVELOPMENT GROUND OPERATIONS SYSTEMS DEVELOPMENT SCIENCE VERIFICATION OPERATIONS HST OPERATIONS M&R PLANNING SUPPORT
instruments
observation problem,
the
time. the
STScI
To is
5-3
Figure
5-3
GSFC Space Organization
The
development,
and
SPACE FLIGHT CENTER
LEAD CENTER
the
Module.
subcontractors.
assembly,
MSFC RESPONSIBILITIES
• • • •
all
amenable
PROJECT SCIENTIST
OFFICE OPERATIONS
l
software factors
compromises. The
ASSEMBLY oPTICAL TELESCOPE PROJECT OFFICE
sophisticated
time-management
Telescope
of
JOHNSON SPACE CENTER
NATIONAL SPACE TRANSPORTATION SYSTEMS PROGRAM OFFICE
SPACE OPERATIONS OFFICE
I
I
STS INTEGRATION AND OPE RATIONS OFFICE
FLIGHT CREW SYSTEMS OFF ICE
1 SYSTEMS INTEGRATION OFFICE
OFFICE ASTRONAUT
i
MISSION INTEGRATION OFFICE
JSC RESPONSIBILITIES: • HST TO SHUTTLE INTERFACES - SHUTTLE SYSTEMS INTEGRATION - SHUTTLE MISSION INTEGRATION • SHUTTLE
ORBITER MISSION OPERATIONS
• HSTTO SHUTTLE CREW INTERFACES - HST DEPLOYMENT - HST M&R PLANNING SUPPORT
Figure the SSM; integration
5-4
JSC
of all Hubble
Space
Space Tele-
scope components; integration testing of the HST once assembled; and support for NASA during ground, flight, and orbital operations. Lockheed will also serve as the HST Missions Operations Space control from
Contractor
Flight and
(STOCC)
(MOC) Lockheed
communicate
the missions
Telescope
5.1.4
Center.
Operations
Hughes ble
for the
testing
the
telescope
was acquired
is now
Systems,
design with
room
contractor, and
Optical
controllers
will
Organization
er coprime
at the Goddard
with
operations
Telescope
Optical
and
called
Inc. The
Telescope
and delivery other
developed
the
Hughes
company
development
the
fine
Danbury
Assembly,
from
verification for integration
components.
guidance
by
is responsi-
through
to Lockheed
HST
recently
They
also
sensors.
in the Space
Control
Center
5.1.5
Scientific
Instrument
NASA
contracted
Contractors
at Goddard. Perkin-Elmer
Perkin-Elmer Connecticut,
Corporation
Corporation the Space
(P-E),
Telescope
tigators of Danbury, project's
oth-
5-4
build
and each
investigator
with specific
subcontractors
scientific in each
instrument. case
principal to
inves-
develop The
is responsible
and
principal for the
Each KENNEDY SPACE CENTER
subcontractor
investigator team the
I
to develop design.
tractor
CARGO MANAGEMENT AND OPERATIONS
part
is the
University
OFFICE
High
VERTICAL PROCESSING DIVISION
same
that
can
sion
goals.
The
instrument
PI and
from subcon-
organization. Robert
An
Bless
responsible
Space the
fulfill
principal
development
In all cases,
teams
the
to assure
ments
the
instruments the
of Dr.
Photometer.
and
Institute
I
of the team
development
NASA
STS CARGO OPERATIONS OFFICE
cases,
of Wisconsin,
Speed
ment
I
with
final working
In some
are
example
works
as an instrument
worked
closely
development
development
for
the
the instru-
Telescope
the Space
at the
with
Science of instru-
Telescope
teams
mis-
are listed
in
Table 5-1. KSC RESPONSIBILITIES • CARGO (HST) OPERATIONS • LAUNCH OPERATIONS
Figure design
KSC Space Organization
and operation
In return, mary
5-5
the Space
time
Many
investigator during
Telescope's
instrument. receives
the first
operational
CONTRACTOR
CONTRIBUTIONS
Telescope
of the specific
the principal
observing
5.2
pri-
months
contractors
uted to the Telescope.
of
and
and their contribution in Table 5-2.
life. DIRECTORS
subcontractors
contrib-
development of the Hubble Space The contractors, subcontractors, to the project
are
listed
OFFICE
R. GIACCONI, DIR P. STOCKMAN, DEP DIR R. MILKEY, ASSOC DIR FOR PM E. SCHREIER, ASSOC DIR FOR OPS
I
_m
EDUCATIONAL & PUBLIC AFFAIRS
SCIENCE PROGRAM SELECTION
E. CHAISSON
N. WALBOM, DEP
PROGRAM MANAGEMENT R. MILKEY
] OPERATIONS
J. CROCKER P. PARKER, DEP JANUARY
]
SCIENCE & ENGINEERING SYSTEMS
SCIENCE COMPUTING & RESEARCH SUPPORT
R. DOXSEY TBD, DEP
R. ALLEN M. SHARA, DEP
M. BREDESON,
1
[
SCIENCE
PROGRAMS
ACADEMIC AFFAIRS
D. MACCHETrO
C. NORMAN S. STEVENS-RAYBURN
B. WHITMORE,
DEP
199O
Figure
5--6
STSci
5-5
DEP
Organization
DEP, AA OPERATIONS
ADMINISTRATION
H. FEINSTEIN G. CURRAN, DEP
SCIENTIFIC SPACE PROGRAMS DIRECTOR B. R. BULKIN
PROGRAM MANAGE R J. C. CARLOCK
APM.-CONTROi.S R. CROZIER MANAGER
MAINTENANCE AND REFURBISHMENT
SYSTEMS ENGINEERING D. J. TENERELLI MANAGER
R. E. GOLDMAN MANAGER
Figure
5-7
LMSC
Space
5-6
Telescope
ENGINEERING AND INTEGRATION A. J. BESONIS MANAGER
Organization
ASSEMBLY AND VERIFICATION C. J. GARDNER MANAGER
Table Instrument] Team
5-1
Faint Object Camera
Instrument
Faint Object Spectrograph
Development
Teams
Goddard High Resolution Spectrograph
(IDTs)
High Speed Photometer
Wide Field/ Planetary Camera
Principal Investigator
E D. Macchetto, European Space Agency
R. J. Harms, Applied Research Corp.
J. C. Brandt, Goddard Space Flight Center
R. C. Bless, University of Wisconsin
J. A. Westphal, California Institute of Technology
Subcontractor
Dornier Corporation British Aerospace Matra- Espace
Martin Marietta Corporation
Ball Aerospace
Space Astronomy Lab, University of Wisconsin
Jet Propulsion Lab
HUGHES DANBURY OPTICAL SYSTEMS HUBBLE SPACE TELESCOPE, OPTICAL TELESCOPE ASSEMBLY PROGRAM MANAGEMENT
VICE PRESIDENT OPERATIONS MANAGER J. D. Rehnperg
I DIRECTOR OTA PROGRAM W S. Ralford
HUNTSVILLE FIELD OFFICE COORDINATOR
CHIEFO_SCIENTIST TA.
H. J. Moeller
I
I
PERFORMANCE MANAGEMENT BUSINESS MGR.
I
SYSTEMS ENGINEERING MANAGER
AND SUPPORT MANAGER ORU MAINTENANCE r D.G. Winehell
L. J. Fad(as
R. J. Esposito
Figure
5--8
Hughes
Facey
Space
5-7
Telescope
Organization
PRODUCT ASSURANCE MANAGER E A, Mirra
Table
5-2
Space
Telescope
Aft Latch. Solar Array
P-E LMSC
Antenna Pointing System
Sperry
Battery
Eagle Picher/GE
Charge Current Controller Circulator Switch Coarse Sun Sensor
LMSC
Computer Data Interface Unit Data Management Unit Deployment Control Electronics Dish and Feed for HGA
Electromagnetic LMSC Rockwell Autonetics LMSC LMSC ESA GE
Responsibilities
Off Load Device
ESA
Optcal Telescope Assembly Optical Control Electronics Oscillator
P-E P-E
Photomu_plier Tube Etectroncs Pointing Sefemode Electronk3s Assembly Power Control Unit Power Distribution Unit
P-E
PrimaryDeployment Mechanism PrimaryMirrorAssembly
P-E
FHST Ught Shade Faint Object Camera Faint Object Spectrograph Fine Guidance Electronics Fine Guk:lance Sensor Fixed Head Star Tracker Focal Plane Assembly
Bendix Domier MMC Harris P-E Ball/Bendix P-E
Forward Latch, Solar Array
LMSC
Goddard High Resolution Spectrograph High Speed Photometer Hinge, Aperture Door Hinge, High Gain Antenna
Ball Aerospace Univ. Of Wis. LMSC LMSC
Image Dissector Camera Assembly Instrument Control Unit Interconnect Cables
P-E LMSC LMSC/P-E et al.
Latch, Aperture Door Latch, High Gain Antenna Low Gain Antenna
LMSC LMSC
MA Transponder Magnetlo Torquer
Motorola Ithaco/Bandix Schoenstadt/Bendix LMSC
MagneOc Sensing System Mechanism Control Unit Metal Matrix Mast Mull_layerInsulation
LMSC
DWA/LMSC LMSC/P-E
Frequency Elect.
Bendix LMSC LMSC ESA P-E Wavecom
RF Multiplexer RF Switch RF Transfer Switch
Elac. Power/Thermal Control Elect.
Contractor
Equipment
Contractor
Equipment Actuator Control Electronics
Equipment
Rate Gym Assembly Reaction Wheel Assembly Retrieval Mode Assembly Rotary Drive
Transco Transco Bendix Sperry Northrop/Bandix Schaeffer ESA Fairchild/IBM Cubic
SAD Adapter SI C&DH SSA Transmitter Secondary Deployment Mechanism Secondary Mirror Assembly Sensor EleCtTOnicsAssembly Solar Array Blanket Solar Array Drive Solar Array DriveElectronics Star Selector Servo
OdelJcs ESA P-E P-E ESA ESA ESA BEI
Temperature Sensor Thermostat/Heater
LMSC/P-E LMSC/P-E
Umbilical Drive Unit
Sperry
Waveguide Wide Field/Planetary Camera
LMSC JPL
SciencelEngineenng
Tape Recorder
Appendix
A
ASTRONOMICAL The
following
presents
astro-
radiating
that
relate
to specific
discus-
is. The
of the Hubble and observations.
Space
Telescope
instru-
lengths,
called
gamma
lengths,
called
radio
nomical
discussion
concepts
sions ments
briefly
CONCEPTS
lengths A.I
ENERGY
AND
WAVELENGTH
energy
are
holes.
objects
Light
energy
is one
released
matter.
The
hydrogen.
sun, The
energy
radiated
Energy
has
stream
They
rate. netic
Photons energy,
energy
portion
of electromagnetic
for
both
example, the
by that
object.
a dual
existence: called
black
For
mostly
the
more
exist together,
and
it is a
yet each
is sepa-
are discrete units of electromagmeasured by counting electrons
operate
this way,
channeling
chemically-coated released electrons.
windows
respect
waves
The
visible
from
short
violet
rays of energy.
Kelvin
degree
that will
waverays
to
to
energy burns
the
is emitted. at
a cooler,
(K) will appear
K star
wave-
A star will
corresponding the peak
a star
degree
12,000
wave-
reddish.
A
appear
blue.
Both
an even
more
ener-
stars
may still be producing
getic rays,
component of emissions, that are invisible.
such
as gamma
it is a constant
photons,
by the photons when The light detectors
3000
shortest
rays, to the longest
color at which
example,
the
waves.
visible
the
and how hot the star
from
the colors
wavelength
up its
burns
object,
released materials.
In some
except
as it burns
hotter
of particles
wave.
radiate
by an object
goes
red, the longest appear
All celestial
in the star
spectrum
and
of electromagnetic
have
plays
an important
part
study field
the universe. components
As the electric and magnetic of light propagate, they
vibration
through
counting
wavelengths
another
property
that
in the way astronomers
vibrate randomly in planes perpendicular to the direction of motion. Figure A-1 illustrates the
they strike certain used in the HST photons
Light
the
of
these
components
of
polarized
light.
ener-
gy are like waves in water. The wave's length is measured from the peak, or crest, of one wave
AGATION DIRECTION
to the
peak
of the
next
wave.
The
length
of a
_- ELECTRIC
FIELD
wave depends upon the temperature of its source. The hotter the source, the shorter the wavelength. at
Different
different
unique
elements
temperatures,
wavelength
radiate and
pattern.
energy
each
A star
has
a
will produce
INTENSITY
different wavelengths depending upon the star's temperature and on what elements exist within the
star
to become
heated
and
radiate
Figure
stars
radiate
a broad
length
spectrum.
trum
of energy
from
the
distinct
contain
many
elements,
range
of energy,
called
Astronomers coming patterns,
study
from
stars
what
Polarized
Light
energy. In
Because
A-1
stars a wave-
the
spec-
to discover, chemicals
are
A-1
certain
through
situations,
however,
magnetized
alignment according trical
and
light
waves.
of the
dust cloud
to the spatial magnetic An
light
clouds
particles
where scatters
orientation field
observer
the light
of the elec-
components looking
passes
of the
in a specific
direction
detects
path
can lead
netic
fields
this polarized
light.
to the discovery
Tracing
of gigantic
its
A.1.2
Resolving
magSpectral
in space.
resolution
closely-spaced detected. A.I.I
Measuring
features
measuring
Wavelengths
are measured in units called There are 10 billion angstrom
angunits
Wavelength
sizes
for the most
energetic
of thousands
of angstroms
Visible
light
4000-7000
range
covers
from
a few angstroms
gamma
rays to hundreds
for long radio
the
spectral
range
peaks
then
dividing
For
example,
to the
human
lengths
are
earth's
eye.
Some
blocked
by dust
atmosphere.
So
detected on earth entire spectrum object.
Figure
wave-
gases
visible
Telescope,
above the wavelengths
earth
A-2
and
the
Space
will be orbiting detect even the ments measure the ultraviolet,
visible
in the starlight
telescopes.
The
wavelengths to 11,000 _,
for a graphic
because
atmosphere, invisible HST
it
can to the instru-
from 1100 ,'_, in in the infrared. See
distance
into the wavelength.
spectral
resolution
features conditions
yield
1000
leO llllllIIIHHII I
2000
I
•,,.-_-.._W
5000
: "'" lO_m
eft lHiilllllflillll
I
3000
| 7000
of
information
2000
concerning
at the astronomical
MEASURING basic
unit
in one
year,
miles.
target.
STARS
measuring
Distance
"apparent"
star's
angular
in reality
Astronomers
the angle objects.
stellar
parallax.
calculated
Parallax
from
simple
caused
of the object.
two positions more
and
"motion"
distant
that angle
A star's
using
of an object,
the star's
against
One-half
by is the
movement
between
in position
ground
can travel
is calculated
in position
view stars
or change
stars
a
six trillion
displacement
change
from
light
parallax.
the observer's
the perceived
distance
is approximately
to nearby
the
calculate
the
the distance
which
measuring
Parallax OTA
llillllllOlll
distinguished,
distance
can
geometry
back-
is called
the
then
(Figure
be
A-3).
illustration.
--ANGSTROMS: I
the two closest be
a
physical
when
is just a small portion of the of energy radiated by that
The Hubble
strongest
are invisible
of the
can
by
that
spectral
The
wavelengths
can be
is calculated
from
Angstroms.
electromagnetic
well
spectrum
between
that
star is the light year:
Most
how
you can see separate wavelengths at 2001 ,_, 2002/_, and so on. These
A.2
waves.
in the
resolution
the distance
means 2000/_,
in one meter. (Another measurement is the nanometer; there are 10 A per nanometer.)
determines
Spectral
wavelength Wavelensths stroms (A).
Wavelengths
t 10,000
| 12,000
stars
measurements
can
relatively
near
(650
light years).
be made
us, generally
only
within
for 200
• • I t
parsecs
I
30,000
the
parallax
Other
F/PC _
tures and distance.
FOC
angle
methods
For greater
is too
exist,
intensity
small
distances, to
measure.
including
using
tempera-
of
to
light,
extrapolate
FOS -,,-HRS -_
Another
HSP----_
tial
type
resolution,
instrument FGS
Figure
A-2
HST
Wavelength
Ranges
A-2
of measurement, determines
forms
an image.
the fineness
of detail
the
angular
resolution,
can
appear
and
angular how
clearly
an
It is a measure
of
in the image. the
or spa-
closer
still be distinguished.
The
greater
two
objects Angular
is how
bright
the
star
would
appear
if it were
viewed placed at a standard distance (10 parsecs). Hence, absolute magnitudes compare the FROM _
POSITION
PHOTO
A
intrinsic
luminosities
dilution
of brightness
Magnitude
TAKEN
ures
objects.
inverted: FROM
TAKEN POSITION
(low
B
by
measurement
large
the
distance.
from
minus
fig-
to plus figures
for
magnitude
positive
brightness)
increasing
objects
The
removing
goes
for the brightest
faint PHOTO
of objects,
scale,
numbers
thus,
indicate
is
faint
objects.
EA RTH' ORBIT
For example, "1 AU
=
DISTANCE
FROM
EARTH
TO
nitude,
SUN
but if you viewed
standard
A-3
Calculating
a Star's
be
visible
is measured
in terms
barely
ible to the unaided nitude Palomar
of the
compo-
of a circle: 360 degrees, 60 arcminutes up one degree, and 60 seconds of arc
make
up one
at 28my
the
angular
times
earth-based mers measure
resolution
better
than
and arcminutes.
stability
of the
in arcseconds.
See
The
(magnitude)
COMPLETE
of
tion. how
the with
Magnitude
ent and
absolute.
bright
tion made
6 apparent
mag-
_360 _'_
IN ONE
CIRCLE
_.._
°
(/(_u-
_
DEGREE
the
telescope
Figure
/_-_ _J0.002"
Further,
the
Figure A-4
Angular
UNIVERSE
EXPANSION
A.3 One
a star
of a celestial
is measured
of the
by
a
two ways: visual
appears
without Absolute
magnitude any
explosion P. Hubble,
appar-
named, is
correc-
expansion distance Law.
magnitude
A-3
key
issues
Telescope
Currently
instrumenta-
Apparent
for its distance.
object
measured
appropriate
MEASURES RESOLUTION BETWEEN STARS
ANGULAR DISTANCE
Measurement
is calculated
A-4.
parameters the
--
largest astronofield of
Space brightness one
eye is about
of
by Mv; star vis-
between
telescopes. In addition, the scientific instruments'
view in arcseconds
telescope,
at a magnitude
or fainter.
stars is measured in arcseconds by the Sis. The finest spatial resolution obtainable with the HST is about one-hundredth of one second of
is
the
to to
IN ONE
pointing
(the
arcminute.
To illustrate,
ten
10 parsecs magnitude)
Parallax
nents make
arc,
mag-
(my); the Hale Telescope on Mount detects stars at 23my; the HST will see
360 DEGREES
resolution
it from
for absolute
visual
+ 4.85. Absolute magnitude is signified apparent magnitude by my. The faintest
stars Figure
apparent
distance
sun would Note that the foreground star in Position B appears to have shifled position with respect to the 'fixed" background stars by an angular displacement of 2p. The parallax of this star is "p", measured in seconds of arc; it is the angle opposite to and bounded at the star by the baseline distance 1 au.
the sun is-26
the
is the
future
universe
astronomers for equals
of the
is expanding
by the universe. from
call the Big Bang.
whom
calculated from
for investigation
the that
a constant
us. Figure
Space the
Edwin
Telescope
velocity (H) times
A-5 charts
the
of
is that
a galaxy's the Hubble
Astronomers 150,000
expanding,
>I-O
._ loo,ooo >_
STARS
that
but possibly
the
more
after
the
Big Bang.
If it slows
verse
may eventually
fall back
Crunch."
"_
calculate
One
indication
universe slowly
is still
than
enough,
right
the uni-
on itself
of a slowing
in a "Big rate
of ex-
pansion would be a decrease in the Hubble constant. To confirm this, however, astronomers o
, ,
50,000
VIEWER
..--
500
1000
1500
DISTANCE
(MEGAPARSECS)
must
measure
requires galactic
The Hubble
velocities
accurately,
which
distances (called
redshifts)
and
in
turn
receding accurately.
Only then can astronomers compare distances and redshifts, through studying galactic move-
2000
ment, Figure A-5
H
measuring
rate
Law
to see whether of expansion.
Hubble
A-4
Space
the universe This
Telescope.
is a major
is slowing goal
its
for the
Appendix
B
ACRONYMS/ABBREVIATIONS
A AB
Angstrom Aft Bulkhead
ACE
Actuator
Control
Electronics
ACS
Actuator
Control
Subsystem
AD
Door
Al
Aperture Aluminum
AS
Aft
BCU
Bus Coupler
C
Celsius
CCC
Charge
CCD CDI
Charge-Coupled Command Data
CEI
Contract
CIT CMD
California Command
cm
Centimeter
CPC CPM
Computer Program Command Central Processor Module
CPU
Central
Processing
CRT
Cathode Coarse
Ray Tube Sun Sensor
CSS
Shroud
Unit
Current
Controller
End
Device Interface
Item
Institute
of Technology
Unit
CU
Control
Unit
CU/SDF
Control
Unit/Science
DCE
Deployment
DCF DIU
Data Data
DMA
Direct
DMS
Data
Management
Subsystem
DMU
Data
Management
Unit
EBA
Electronics Bay Assembly Electron Bombarded Silicon
EBS ECA
Control
Capture Interface
Electronics Electronics
EOR
End
EPS EPTCE
Electrical Electrical
ES
Equipment
ESA EVA
European
Formatter
Electronics
Facility Unit
Memory
ECU
Data
Access
Control Control
Assembly Unit
of Record
Extravehicular
Power Power
Subsystem Thermal Control
Section Space
Agency Activity
B-1
Electronics
F
Fahrenheit
FCA FGE
Figure Control Fine Guidance
Actuator Electronics
FGS
Fine
Sensor
FHST
Fixed
Head
FOC
Faint
Object
Camera
FOS
Faint
Object
Spectrograph
FOSR FOV
Flexible Optical Field of View
FPS
Focal
FPSA
Focal Plane Structure Forward Shell
FS FSS ft G/E
Guidance Star
Plane
Flight Feet
Solar
Support
GGM
Gravity
GSFC
Goddard
GSTDN
Ground
HGA
High
Gain
HRS
High
Resolution
HSP
High
Speed
HST
Hubble
Hz
Hertz
I&C
Instrumentation
IBM
International
IDT
Image Inches
Gradient Space
Mode Flight
Spaceflight
(Maryland) and
Data
Network
Spectrograph
Photometer
Space
Telescope
(Cycles
per Second) and
Communications
Business
Dissector
Input Output Infrared
JPL
Jet
JSC
Johnson
k
Kilo (1000)
kbytes
Kilobytes
kg km
Kilogram Kilometer
KSC
Kennedy
lb LGA
Pound
Propulsion
Gain
Center
Tracking
Antenna
IR
Low
Assembly
Structure
Graphite-Epoxy General Electric
IOU
Reflector
Structure
GE
in
Tracker
Space
Space
Machines
Tube/Instrument Unit
Laboratory Center
Center
Antenna
B-2
(Subsystem) Corporation Development
Team
LMSC L
LOS
Lockheed Missiles Line of Sight
LS
Light
m
Meter
MA
Multiple
MAT M&R
Multiple Access Transponder Maintenance and Refurbishment
MCU
Mechanisms
Control
MDB
Multiplexed
Data
MgF 2 MHz
Magnesium
Fluoride
mi MLI
& Space
Company,
Shield
Access
Unit
Bus
Megahertz Miles
mm
Multilayer Millimeter
MM
Maintenance
MMC MP
Martin Marietta Corporation Maintenance Platform
MR
Main
Ring
MRA
Main
Ring
MSFC
Marshall
MSS
Magnetic
Sensing
MTA
Metering
Truss
Assembly
MTS
Metering
Truss
Structure
MU
Memory
Unit
Mv
Absolute
Visual
Magnitude
mv
Apparent
Visual
Magnitude
NASA NCC
National Aeronautics and Space NASA Communications Network Network Control Center
nm
Nanometers
nm NSSC-I
nautical
miles
NASA
Standard
Spacecraft
OCE
Optical
Control
Electronics
OCS
Optical
Control
Subsystem
ORU
Orbital
Replaceable
OTA
Optical
Telescope
P-E
Perkin-Elmer
PC
Planetary
PCEA
Pointing
Control
Electronics
PCS
Pointing
Control
Subsystem
PCU
Power Photon
NASCOM
PDA
Inc.
Insulation Mission
Assembly Space
Flight
Center
System
Administration
Computer,
Model-I
Unit Assembly
Corporation
Camera
Control Unit; Power Detector Assembly
Assembly Convertor
B-3
Unit
(module
of DF-224)
PDM PDU PI
Primary Deployment Power Distribution
Mechanism Unit
PIT
Principal Processor
PM
Primary
Mirror
PMA
Primary
Mirror
PMT PN
Photomultiplier Pseudo-Random
POCC
Payload
PSEA PWR
Pointing/Safemode Power
RAM
Random-Access
RBM
Radial
RGA RIU
Rate Gyro Assembly Remote Interface Unit
RM
Remote
Module
RMGA
Retrieval
Mode
RMS
Remote
ROM
Read-Only Memory Reed-Solomon
RS RSU
Investigator; Payload Interface Table Assembly Tube Noise
Operations
Control
Center
Electronics
Assembly
Memory
Bay Module
Gyro
Manipulator
Assembly System
RWA
Rate Sensing Unit Reaction Wheel Assembly
S&M
Structures
S/N
Signal-to-Noise
SA SAT
Solar
and
Mechanical
(Subsystem)
Ratio
Array
SAA
Single South
SAD
Solar
Array
Drive
SADE
Solar
Array
Drive
Electronics
SADM
Solar
Array
Drive
Mechanism
SBA
Secondary Baffle Stored Command
SCP
Interrogator
Access Atlantic
Transponder Anomaly
Assembly Processor
SD SDF
Science
Data
Science
Data
SDM SI
Secondary Scientific
SI C&DH
SI Control
SiO2 SIPE
Silicon Scientific
Instrument
SM
Secondary
Mirror
SMA
Secondary
Mirror
SPC
Stored
SSC
Science
SSE
Space
Formatter
Deployment Instrument and
Data
Mechanism Handling
(Subsystem)
Dioxide
Program Support Support
Payload
Enclosure
Assembly Command Center
Equipment
B-4
SSM SSM-ES SSP SS STDN STINT STOCC STS STScl TCE TCS TDRS TDRSS TiO2 TLM TRW TYP UCSD ULE m UV
Support
Systems
Module
SSM-Equipment Standard Switch
Section Panel
Safing
System
Space (flight) Tracking Standard Interface
and
Data
Space Space
Telescope Operations Transportation System
Space
Telescope
Science
Network
Control
Center
Institute
Thermal
Control
Electronics
Thermal
Control
Subsystem
Tracking
and
Data
Relay
Satellite
Tracking Titanium
and Data Dioxide
Relay
Satellite
System
Telemetry Thompson
Ramo
Woolridge,
Inc.
Typical University
of California,
Ultra Low Micrometer, Ultraviolet
Expansion one millionth
V V1,V2,V3
Volt
W WFC WF/PC
Watt
HST
Wide
San
of a meter
Axes
Field
Camera
WT
Wide Field/Planetary Weight
ZOE
Zone
Diego
Camera
of Exclusion
B-5
Appendix GLOSSARY
C
OF TERMS
-A-
Acquisition,
target
Adjusting the HST ment's aperture.
position
to place
incoming
target
light
in an instru-
Aft
The
Altitude
Height
Aplanatic
Image
Aperture
Opening
Arcsec
A wedge of angle, makes up the sky.
1/3600th of one degree, in the 360-degree "pie" that An arcminute is 60 seconds; a degree is 60 minutes.
Apodizer
A masking
that
Astigmatism
A defect
Astrometry
Measurement
Astrophysicist
Scientist
Attitude
Orientation
rear
of the
spacecraft.
in space. corrected that
everywhere allows
device that
who
in the field
light
to fall onto
blocks
prevents
sharp
of star
positions
studies of the
the
stray
of view.
an instrument's
optics.
light
focusing. in relation
physics
spacecraft's
To other
stars
of astronomy. axes
relative
to the
earth.
-BBaffle
Material
that
extracts
stray
light
from
the
incoming
image.
-CCassegrain
A type of telescope longer focal length
that reflects or "folds" the incoming in a short physical length.
Changeout
Exchanging
Collimate
To straighten
Coma
Image
Concave
A mirror
surface
that
bends
outward
to expand
Convex
A mirror
surface
that
bends
inward
to concentrate
Coronographic
A device
that
a unit
light
to have
on the satellite.
or make
abberations
parallel
that
allows
two light
paths.
give it a "tail".
viewing
a light
object's
an image. an image.
corona.
-DDiffraction Drag,
grating
atmospheric
Split Effect
light
into
a spectrum
of atmosphere
of the
that slows
(3-1
component
a spacecraft
wavelengths and forces
its orbit
to decay.
a
-E-
Electron
A small
Ellipsoid Extravehicular
A surface Outside
particle
of electricity.
with
only circular
the spacecraft;
planes.
activity
in space
conducted
by suited
astronauts.
-F-
Focal plane
The axis or geometric telescope.
Hyperboloidal
A slightly deeper primary mirror.
plane
curve,
where
the
mathematically,
incoming
light
is focused
than
a parabola;
by the
shape
of the
that
is not a
-l-
Interstellar
Between celestial objects; often star, such as clouds of dust and
refers gas.
to the matter
in space
-LLight
year
The distance
Luminosity
The
traveled
intensity
by light in one year,
of a star's
approximately
six trillion
miles.
brightness.
-M-
Magnitude,
absolute
How
bright
Magnitude,
apparent
How bright distance.
a star
appears
the star
would
without appear
any correction if it were
viewed
made
for its distance.
placed
at a standard
-N-
Nebula
A mass of luminous lar nova.
Nova
The
explosion
interstellar
dust and gas, often
of a star. -O-
Occultation
Eclipsing
Orientation
Position
one
body
in space
with
another.
relative
to the
(;-2
earth.
produced
after
a stel-
-pParallax
The "apparent" angular movementof an object, causedin reality by the observer's movement, not the object.
Photon Pixel
A unit of electromagnetic energy.
Polarity
A single element of a detection device. Light magnetizedto movealong certainplanes;polarimetric observation studiesthe light moving along a given plane.
Prism
A device that breaks light into its composite wavelengthspectrum. -Q-
Quasar
A quasi-stellar
object
of unknown
origin
or composition.
-R-
Radial
Perpendicular to a plane; i.e., instruments from the optical axis of the HST.
Reboost
To boost decayed
the
satellite
because
back
into
placed
its original
of atmopspheric
at a 90-degree
orbit
after
orbit
has
drag.
Resolution, spectral
Determines how well closely-spaced can be detected.
Resolution, angular
Determines
Ritchey-Chretien
A type of Cassegrain (folded) telescope where both primary mirrors are hyperboloidal to correct for image aberrations.
how clearly
the
angle
features
an instrument
forms
in the wavelength
spectrum
an image. and seconary
-S-
Spectral devices
A spectrograph is an instrument that photographs the spectrum of light within a wavelength range. A spectrometer measures the position of spectral lines. A spectrophotometer determines energy distribution in a spectrum.
Spectrum
The
wavelength
range
of light
in an image.
-T-
Telemetry
Data
and
commands
sent
from
the
spacecraft
-U-V-W-
Wavelength
The
spectral
range
of light
0-3
in an image.
to the
ground
stations.
Appendix NASA
The
Contract
proposed scope
SPECIFICATIONS
End
Item
by NASA and
demands
the are
ce/operating
requirements,
duling
and
In addition,
accumulates, new ments will arise.
D.1
18
HST
Position.
The
project
outside
require-
going
within
analyses,
most
listed
trade
important
below,
the consideration
studies,
of
and evaluations.
system
requirements
Door. the
The door
modes tem and
are
coarse
object
and
tracking,
The
fine
PCS
door
scanning,
will remain
slew
to within
even
if the
sun is normal
open,
70R
or to within
Management
5000
bytes
operating
bytes
(Mb)
solar-sys-
engineering
pointing,
will close
of the V1 axis. During
limb of the earth moon.
Data
System.
opening,
but
of the
the
bright
15R of the bright
are
by system.
Control
will be no direct
roll on the V1 axis.
reprogrammable, Pointing
positions
into the aperture
20 degrees
PCS will not
on the V3
of the sun -- with
a five-degree
operation,
mission
for
position
plane
Viewing
50 degrees
Aperture
REQUIREMENTS
The
more
spacecraft
the sun in the V1-V3
sunlight with
reflect
minutes
normal
side of the spacecraft.
this
two
settling.
as the mission
about
HST will slew 90 degrees
with
will place
mission-derived
requirements
the
minutes,
viewing/sche-
PERFORMANCE/OPERATING
These
TELESCOPE
The
performan-
and
knowledge
in
Tele-
instruments.
SPACE
For maneuvering,
of the sub-
in two categories:
requirements.
progresses
Space
on each
scientific
requirements
THE HUBBLE
Specifications
for the Hubble
put exacting
systems
(CEI)
FOR
D
maneuvering,
OTA,
Subsystem. with
(words) data.
data,
is of
125 million
and
It will receive
engineering
DMS
capability
for commands,
for science
and SSM
The
a storage
12.5
Mb for
and merge
SI,
data.
contingency. Instrumentation
In Coarse
Pointing
the PCS will point 99%
of the
time.
PCS will place aperture
to within In Fine
a target
of the more
Object minimum
0.007
Tracking
30 arcsec
of a target
Pointing
Mode
of 0.01 arcsec The arcsec.
Mode,
of three
with an angular second.
the
the
arcmin
velocity
FGS), the
in any SI entrance
observation.
than
(without
star
with an accuracy
length move
Mode
Subsystem.
for the
image
cannot
In Solar
System
PCS will provide tracking
a
mission orbit.
square
for an aperture
at a speed sized
scan
fields
up to 1
of up to 40 arcsec/sec,
from
The
minimum
time is 20 minutes
Electrical
the HST should
(I & C) will
use
the
possible
of scientific
transdata per
per
of 2800 arcmin
subsystem
single-access channel. The system should be able to transmit science and engineering data
Power
can provide For scanning,
Communication
I&C
multiple-access channel for commands, tracking, and real-time engineering telemetry. High data-rate scientific data will transmit via the
simultaneously.
for objects
of up to 0.21 arcsec
and The
0.1 to 10 arcsec.
than
D-1
a maximum
W during
Sis for two years, battery
charge 20%,
Subsystem.
even
average
each even
drain
orbit if one
over
with
The
solar power
output
for the OTA
and
battery
The
24 hours one
arrays
battery
fails.
will be less out.
The
battery
charger
can
recharge
batteries
com-
completely
within
the
orbital
Control
Subsystem.
tem
is passive,
protecting
the
OTA,
and
shroud
Sis, power
thermal
all SSM
SI C&DH.
can accommodate
sipating
The
loads
sys-
equipment,
The
heat of 300
SSM
radiated
aft
by dis-
to 500 W.
Arrays.
in any
The
of
temperature.
face
period
will do
together
is an
power,
operational
thermal,
OTA. The energy
and
OTA
from
sec radius,
scientific
instruments
used based
data-management
can capture
a star held
decision
70%
(starlight)
on
within
for up to 24 hours.
a 0.01 arcThe
optical
image will be at least 38% at 1216 A and 55% at 6328 A; higher spectral ranges make up the rest to 70%. single
The
OTA
object)
nal-to-noise
can
of (S/N)
integration
time.
laxies,
surface
the
25 mv/arcsec
at
resolve least
ratio
point 27my
brightness
2, resolved
with a S/N ratio time.
sources with
of 10 after
For extended
(a
a sig-
four
hours
objects
like
can
be
at least
0.25
arcmin
to at least
of 10 for 10 hours
the
sun within
ga-
integration
basic
viewing
ing
system
using
certain
objects,
such
as the
moon
with
and
stray
earth,
light
can
opening,
and
or when
lunar-eclipse The
South
of weak
Atlantic
terrestrial
FGS
will
detect
guide
charged
of
14my
target
can stars
calculate
the
in the
FOV
angular
position
within
10 minutes.
are within be as
impacting calculated
(SAA)
is a region
particles
to reach
noise the
low alti-
by these
spacecraft other noise.
allows
WFPC and FOC and FGS opera-
generated
by formula.
which
goes
par-
beyond
Loss of FGS pointSis normally
oblivi-
or
brighter. The time from search to detection, for a 30-arcsec radius, is 150 s. In addition, each FGS
ticles
when
and earth
field
ing could also impact ous to this radiation stars
telescope
observation.
magnetic
limit
The
the
an
Anomaly
degrees
earth.
or light-reflect-
observations.
the
of the sunlit
sun flood
aperture. Exceptions may authorization, such
tions,
70 degrees
to avoid above cervia the
guidelines.
ruin
the moon
15 degrees of the given special
energetic
and
are
Requirements are to avoid observations when the sun is within 50 degrees of the aperture
Stray light at the focal plane will be less intense than a 23Mv star when the HST points within 50 of the moon,
sur-
5-5/8 degrees solar array
requirements
could preclude and calibrations,
15 degrees
cell
degrees.
less than during
tudes. This observations
of the sun,
assumes
five
bright objects, curtail observations tain noise levels, and communicate
Bright
of the incident
4000
REQUIREMENTS
TDRS
needs.
will provide
VIEWING/SCHEDULING
The number
arrays
Positioning maneuvers cannot be performed
of 750 W for
10-minute
The solar
This
faces
D.2
three seconds no harm.
limits.
designed
with
power
is within
two years in orbit, even loss factors, at the
operation.
A peak
of
W or more at 34 V after with diode and other
Sis, SI C&DH. Scientific instrument power will be less than 150 W for 28V, or 530 W when used the SI C&DH.
average
average
of 803 W as long as
five orbits. Solar
Thermal
with an orbital
665 W for 27V, with a peak
pletely every orbit during normal conditions. After an abnormal roll maneuver, battery energy will replenish
The OTA will operate
of 10
TDRSS
"limb"
D-2
scheduling
with the STOCC, also can affect can block
impacts
any communication
and atmospheric communications. transmission
interference The earth
if the HGA
beam
a
is intercepted affect
by the
limb.
communications
antennas.
Solar
static
for the TDRS
No transmission
TDRS
is in earth
within
radio-frequency
is possible
shadow,
or when
also can or ground when
the
HST
the is
interference.
O-3
STScI
administration
needs
will dictate
requirements.
or individual other
viewing
observation or scheduling
Appendix ORBITAL Table
E-1
lists
component
each
considered
Hubble
Space
a replaceable
Description
E
REPLACEABLE
Telescope unit,
the
"lhble
E-1
UNITS
number of each and its location
HST
No
Location: (1, SSM
Battery
6
(2,3,
FGE
3
(D,F,G,
SI C&DH
1
(10,
RWA
4
(6,9,
SSM
RSU
3
SSM
Shelf
RGE/ECU
3
(10),
SSM
Computer
carried
ORUs
1
DF-224
component on-board.
(Bay)
or Other
ES)
SSM
ES)
OTA
SSM
ES)
ES) ES)
Shelf
12
(4), SSM
Shelf
Box
2
Fwd face
of SSM
SA (Stowed)
2
Along V1, +V2
RBM
3
In FPSA,
+ V2,
(FOS/WFS)
V3 Radial
Bay
WF/PC
In FPSA,
-V3
Radial
Bay
HRS
In FPSA,
Axial
Bay
1 (+V2,
FOS
In FPSA,
Axial
Bay 2 ( + V2, -V3)
FOC
In FPSA,
Axial
Bay 3 (-V2,
-V3)
Axial
Bay 4 (-V2,
+ V3)
Fuse
Plug
Diode
HSP
1
In FPSA,
DMU
1
(1, SSM
ES)
MAT
2
(5, SSM
ES)
SADE
2
(7, SSM
ES)
TR
3
(5, 8, SSMES)
EP/TCE
1
(H),
OTA
ES
DIU
4
(B), OTA
ES
OCE
1
(C),
ES
MCU
1
(7, SSM
ES)
SAT
2
(5, SSM
ES)
E-1
OTA
ES
& +
+V3)
on the HST,
