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Astrophysics Science Division | Sciences and Exploration

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Acronyms & Glossary

Hubble Space Telescope Acronyms List


ACS Advanced Camera for Surveys - This will consist of three electronic cameras 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; to be installed during SM3B in 2001.

ASLR(K) Aft Shroud Latch Repair (kits) - This kit will fix door latches in the aft shroud area of the Telescope that have been damaged by extreme temperature changes and high torques

BAPS Berthing and Positioning System - This is the unit that holds and maneuvers HST while it is berthed 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 robot arm.

BPS BAPS Support Post - This post is installed to keep the BAPS immobile during activities which generate high torques on the HST, for example reboost.

C-5 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

COSTAR Corrective Optics Space Telescope Axial - 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

DF-224 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 positions.

FOC Faint Object Camera - First Generation Imaging camera. FOC is used to image very small field of view, very faint targets. Last first generation instrument on HST

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 during Servicing.

GHRS Goddard High Resolution Spectrograph - First Generation Spectrograph. GHRS was used to obtain high resolution spectra of bright targets

GSFC Goddard Space Flight Center - Greenbelt, Maryland. The HST Project is run from here.

HOST mission Hubble Space Telescope Orbital Systems Test (1998) - This mission tested several pieces of equipment in preparation for SM3A and SM3B.

HST Hubble Space Telescope

KSC Kennedy Space Center, Cape Canaveral, FL - 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 �m thick polyester or polyamide layers sewn together. It is often silver or gold in color.

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 science operations.

NICMOS Near Infrared Camera and Multi-Object Spectrometer - Second Generation Imager/Spectrograph. NICMOS is HST's only NIR instrument.

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 mounted

OCE-EK Optical Control Electronics Enhancement Kit

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 units.

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.

RSU Rate Sensor Unit - The gyroscopes are part of Hubble's pointing system. They provide a frame of reference for Hubble to determine where it is pointing and how that pointing changes as the telescope moves across the sky. They report any small movements of the spacecraft to Hubble's pointing and control system computers. The computers then command the spinning reaction wheels to keep the spacecraft stable or moving at a desired rate. 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

SM1 First HST Servicing Mission, December 1993

SM2 Second HST Servicing Mission, February 1997

SM3A HST Servicing Mission 3A, December 1999

SM3B HST Servicing Mission 3B, planned for 2001

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 m2 (86,000 ft2) facility designed to provide support for the integration and testing of spacecraft hardware. It is unique in the fact that it contains a 36,816m3 (1.3M ft3) 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 recorder

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 Center - Located at Goddard Space Flight Center, the STOCC is where all commanding to the HST originates from.

STS Space Transportation System - This is the formal name of the Space Shuttle Program

STScI Space Telescope Science Institute - This institute, located at Johns Hopkins University, is the home of the HST Scientists. 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 Kit - These protect Hubble's batteries from overcharging and overheating when in safe mode

WFC3 Wide Field Camera - Wide Field Camera 3. Fourth Generation Imaging camera. This camera will supplement ACS and guarantee imaging capability for HST after the fourth Servicing Mission

WFPC Wide Field/Planetary Camera. The camera currently in use is the second-generation instrument WFPC2, installed during the First Servicing Mission in December 1993. It replaced WFPC1 and was built with optics to correct for the spherical aberration of the primary mirror.