NASA Logo, National Aeronautics and Space Administration

National Aeronautics and Space Administration

Goddard Space Flight Center

Astrophysics Science Division | Sciences and Exploration

This website is kept for archival purposes only and is no longer updated.

Space Dog CosmicKids Servicing Mission 3A
CosmicKids Main Classroom HST Parts & Instruments Cool Links SM3A Home

Hubble Space Telescope Parts & Instruments


Selected by the sciLINKS program,
a service of National Science Teachers Association. Copyright 2001.

Hubble Parts Definitions


Solar Arrays (2)
Convert sunlight into electricity in order to power the telescope.
Communications Antennae
Transmit Hubble's information to communications satellites called the Tracking & Data Relay Satellite System (TDRSS) for relay to ground controllers at the Space Telescope Operations Control Center (STOCC) in Greenbelt, Maryland.
Aperture Door
Protects Hubble's optics in the same way a camera's lens cap shields the lens.
Multi-Layer Insulation
Protects Hubble from extreme temperatures.
Outer Thermal Blanket Layer
Protects Hubble from the harsh space environment with stainless steel sheets.



inside inside

Spacecraft Computer
Serve as the master control system (monitors health, controls movement, holds observation targets).
Supply power when Hubble is in the Earth's shadow (charged by solar power from the arrays during daylight).
Sunlight powers Hubble and recharges the batteries. Six batteries power Hubble at night.

Pointing Control System
Keeps Hubble steady, measures distances, and finds and keeps a target in sight.

  Gyroscopes/Rate Sensor Units
Continually report Hubble's position and sense any movement of the telescope. Each Rate Sensor Unit holds two gyros.
  Reaction Wheels
Spin to rotate the telescope to a new target.
  Magnetic Torquers
Slow the speed of the reaction wheels.
  Star Trackers
Find pre-selected "landmark" stars to serve as reference points.
  Fine Guidance Sensors (2)
Keep Hubble precisely locked on its target.


Instrument Support Structure
Holds instruments in place.
Telescope Support Structure
Holds primary and secondary mirrors in place using special material that will not expand or contract.



Primary Mirror
Collects light from space and reflects it to the secondary mirror.

Secondary Mirror
Collects light from the primary mirror and reflects it through a hole in the primary mirror to the focal plane.


More on Hubble Instruments

Faint Objects Camera (FOC)
FOC is the last original instrument still on Hubble, the FOC was designed to see crisp, clear images of very faint objects. FOC is no longer operating and is to be removed in 2001. It will be replaced with the Advanced Camera for Surveys (ACS).

Space Telescope Imaging Spectrograph (STIS)
[Replaced the Faint Object Spectrograph (FOS) in 1997]
This second-generation instrument separates light into colors or wavelengths, much like a prism makes a rainbow. Scientists use this information to learn what stars and other objects are made of and how they move. STIS is an especially good black hole hunter.

Wide Field Planetary Camera 2 (WFPC2)
[Replaced WFPC1 in 1993. . WFPC2 will be replaced by Wide Field Camera 3 in 2003.]
This powerful camera takes crystal-clear pictures over a wide field of view and broad range of wavelengths.

Near Infrared Camera & Multi-Object Spectrometer (NICMOS) [replaced Goddard High-Resolution Spectrograph (GHRS)]
NICMOS is a Second Generation Imager/Spectrograph. NICMOS is HST's only near infrared (NIR) instrument. To be sensitive in the NIR, NICMOS must operate at a very low temperature, requiring sophisticated coolers. Problems with the solid Nitrogen refrigerant have necessitated the installation of the NICMOS cryo-cooler on Servicing Mission 3B to continue operations.

NICMOS Cryo-Cooler (NCC)
Like COSTAR, NCC is not a separate instrument but rather a device which will allow NICMOS to continue operations by providing mechanical cooling for the NICMOS detectors. Results from the HOST mission indicate that NCC will allow NICMOS to operate for up to 5 years beyond Servicing Mission 3B.

Solid State Recorder (2) (one in use, one spare)
[First SSR replaced a reel-to-reel, mechanical tape recorder in 1997.]
Digitally records and stores science and operations data. This is the second solid state recorder to be placed on Hubble. It serves as a spare to the first SSR.

S-Band Single Access Transmitter (SSAT) (2)
Sends data over radio waves to a system of satellites, that then relay the information to Hubble's controllers on the ground. Hubble uses two of these transmitters.


Back to Top

SM3A Mission Overview Additional Mission Information and Timeline Daily Mission Updates Space Telescope Operations Control Center Image Gallery Cool Links
Video Feeds Mission Chronicles CosmicKids Shuttle Crew Information Glossary
Content Last Updated: 12/27/99