ACS Advanced Camera for Surveys
This will consist of three electronic channels and a complement
of filters and dispersers that detect light from the ultraviolet
at 1200 angstroms to the near infrared at 10,000 angstroms, with
10 times the efficiency of current instruments.
ASLR(K) Aft Shroud Latch Repair (kits)
This kit will fix door latches in the aft shroud area of the Hubble
that have been damaged by extreme temperature changes and high
BAPS Berthing and Positioning System
This is the unit that holds and maneuvers HST while it is attached
to the orbiter. The BAPS can orient the telescope at a variety
of angles and can rotate the HST a full 360 degrees to bring any
part of HST within the reach of the astronauts and the RMS, or
BPS BAPS Support Post
This post is installed to keep the BAPS immobile during activities
which generate high torques on the HST, for example during reboost.
A heavy logistics global transport aircraft designed to provide
massive strategic airlift and express delivery of padded or oversized
cargo as well as passengers; transported HST flight hardware and
personnel to and from GSFC and KSC.
COS Cosmic Origins Spectrograph
Fourth Generation Spectrometer. COS is an ultraviolet spectrograph
optimized for observing faint point sources with moderate spectral
resolution. To be installed during SM4 in 2004.
COSTAR Corrective Optics Space Telescope
Second Generation Corrective Optics. COSTAR is not an actual instrument,
it consists of mirrors which refocus the abberated light from
the HST optical system for first generation instruments. Only
FOC utilizes its services today. It has been deactivated since
FOC will be removed during SM3B.
Onboard Digital Fixed Point 2's complement 24-bit word Rockwell
computer module. This is the main computer which controls the
attitude (orientation) of the Hubble Space Telescope.
ESA European Space Agency
EVA Extravehicular activity
outside the spacecraft; activity in space conducted by suited
astronauts. This is also known as a spacewalk.
FGS Fine Guidance Sensor
Science/Guidance instruments. The FGS's are used in a "dual-purpose"
mode serving to lock on to "guide stars" which help
the telescope obtain the exceedingly accurate pointing necessary
for observation of astronomical targets. These instruments can
also be used to obtain highly accurate measurements of stellar
FOC Faint Object Camera
First Generation Imaging camera. FOC is used to image very small
field of view, very faint targets. The last of the original instruments
FOS Faint Object Spectrograph
First Generation Spectrometer. FOS was used to obtain spectra
of very faint or far away sources. FOS also had a polarimeter
for the study of the polarized light from these sources.
FSS Flight Support System (Structure)
This is the name for the structure which holds HST and provides
power and computer interfaces while it is berthed to an Orbiter
GHRS Goddard High Resolution Spectrograph
First Generation Spectrograph. GHRS was used to obtain high resolution
spectra of bright targets. It was removed during SM2 in 1997.
Parts of GHRS are being reused for COS.
GSFC Goddard Space Flight Center
Greenbelt, Maryland. The HST Project is located here.
HOST mission Hubble Space Telescope
Orbital Systems Test (1998)
This mission tested several pieces of equipment in preparation
for SM3A and SM3B. Designated shuttle mission STS-95.
HST Hubble Space Telescope
KSC Kennedy Space Center, Cape Canaveral,
KSC is responsible for launches.
MLI Multi-layer insulation
This is the highly reflective material which is attached to spacecraft
to act as a thermal barrier. It consists of many sheets of 25
µm thick polyester or polyamide layers sewn together. It
is often silver or gold in color.
MULE Multi-use Lightweight Equipment
One of the transport modules used in the shuttle's bay. For SM3B,
the mule will transport the Nicmos Cooling System (NCS).
NASA National Aeronautics and Space Administration
NCS NICMOS Cooling System
This mechanical cooler which was tested during the HOST mission
and will be installed during SM3B will allow NICMOS to resume
NICMOS Near Infrared Camera and Multi-Object
Second Generation Imager/Spectrograph. NICMOS is HST's only NIR
NIR Near Infrared
Near Infrared light is not visible to human eyes, but many celestial
objects shine brightly with this light. Typically associated with
heat, NIR images show the presence of molecules and complex compounds.
NOBL New Outer Blanket Layer
The NOBL are stainless steel panels covered with a protective
thermal coating. These panels fit over existing, degraded insulation
on Hubble's exterior surface, to control Hubble's internal temperature.
In 1997, astronauts on Servicing Mission 2 discovered damaged
areas of insulation and performed temporary repairs. The NOBL
will be permanently attached.
OCE-EK Optical Control Electronics Enhancement
ORU/ORI Orbital Replacement Unit /
Orbital Replacement Instrument
Since HST was designed to be serviced on-orbit, many of the systems,
and all of the instruments were designed and built as replaceable
ORUC Orbital Replacement Unit Carrier
Special boxes which isolate the delicate instruments and other
ORUs from the forces and vibrations of launch and ascent to orbit.
PCU Power Control Unit
Hubble's power switching station. The PCU controls and distributes
electricity from the solar arrays and batteries to other parts
of the telescope.
RAC Rigid Array Carrier
One of the transport modules used in the shuttle's bay.
For SM3B, the RAC will transport the new solar arrays (SA3) and
bring back the old ones (SA2).
RSU Rate Sensor Unit
Hubble houses three RSU's and each RSU contains two gyroscopes.
The gyroscopes are part of Hubble's pointing system. The gyroscopes
work by comparing Hubble's motion relative to the axis of the
spinning masses inside the gyroscopes. In the absence of external
forces, these axes remain stable relative to the fixed stars in
the sky. By keeping Hubble fixed relative to these axes, Hubble
stays stable relative to the stars.
SA3 Solar Array 3
Hubble's new solar arrays which will be installed on servicing
mission 3B. Although 45 percent smaller than its predecessors,
they will produce 25 percent more power.
SAC Second Axial
One of the transport modules used in the shuttle's bay.
For SM3B, the SAC will transport the Advanced Camera for Surveys
SM1 HST Servicing Mission 1, December 1993
SM2 HST Servicing Mission 2, February 1997
SM3A HST Servicing Mission 3A, December 1999
SM3B HST Servicing Mission 3B, planned for
SSAT S-band Single-Access Transmitter
This replacement transmitter uses radio waves to send data to
the ground. The older unit it replaces will be returned to Earth
and refurbished for a later flight.
SSDIF Spacecraft Systems Development
and Integration Facility
This building is located at GSFC. The SSDIF is a 7,989 square
meters (86,000 square ft) facility designed to provide support
for the integration and testing of spacecraft hardware. It is
unique in the fact that it contains a 36,816 cubic meters (1.3
million cubic ft) horizontal, unidirectional flow cleanroom. Additional
features include: Automated Data Processing Area, Shipping/Receiving
Area, Flight Hardware Storage Area, and Precision Cleaning facilities.
SSR Solid State Recorder
Hubble's original data recorders were mechanical, reel-to-reel
tape recorders with many moving parts that wear out over time.
The digital SSR has no moving parts or tape to break, so it is
much more robust. This next-generation recorder is faster and
more reliable, and it can store 10 times as much data as a mechanical
SSRF Shell/Shield Repair Fabric
Sheets of flexible, aluminized Teflon® fabric that fit over
the original multi-layer insulation on Hubble's forward shell
and light shield to add thermal protection. In 1997, astronauts
on Servicing Mission 2 discovered damaged areas of insulation
and performed temporary repairs. The SSRF will be permanently
mounted over these temporary coverings.
STIS Space Telescope Imaging Spectrograph
Second Generation Imager/Spectrograph. STIS is used to obtain
high resolution spectra of resolved objects. The special ability
of STIS is to simultaneously obtain spectra from many different
points along the target.
STOCC Space Telescope Operations Control
Located at Goddard Space Flight Center, the STOCC is where all
commanding to the HST originates.
STS Space Transportation System
This is the formal name of the Space Shuttle Program.
STScI Space Telescope Science Institute
This institute, located at the Johns Hopkins University campus
in Baltimore, is the home of HST science operations. The STScI
is responsible for allocating observing time and for calibration,
data storage, retrieval, and distribution of science data. STScI
also provides software tools for manipulating the data.
USAF United States Air Force
USN United States Navy
USS United States Ship
VEST Vehicle Electrical Systems Test
Hubble high fidelity mock-up trains astronauts on installation
and removal of flight hardware components.
VIK Voltage/Temperature Improvement
These protect Hubble's batteries from overcharging and overheating
when in safe mode.
WFC3 Wide Field Camera 3
Fourth Generation Imaging camera. This camera will supplement
ACS and guarantee imaging capability for HST after Servicing Mission
WFPC Wide Field/Planetary Camera
The dual-channel (visible and near-IR) camera currently in use
is the second-generation instrument WFPC2, installed during Servicing
Mission 1 in December 1993. It replaced WFPC1 and was built with
optics to compensate for the spherical aberration of the primary