Space Telescope Parts & Instruments
by the sciLINKS program,
a service of National Science Teachers Association. Copyright 2001.
sunlight into electricity in order to power the telescope.
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,
Hubble's optics in the same way a camera's lens cap shields the lens.
Hubble from extreme temperatures.
Thermal Blanket Layer
Hubble from the harsh space environment with stainless steel sheets.
as the master control system (monitors health, controls movement,
holds observation targets).
power when Hubble is in the Earth's shadow (charged by solar power
from the arrays during daylight).
powers Hubble and recharges the batteries. Six batteries power Hubble
Hubble steady, measures distances, and finds and keeps a target
Continually report Hubble's position and sense any movement
of the telescope. Each Rate Sensor Unit holds two gyros.
Spin to rotate the telescope to a new target.
Slow the speed of the reaction wheels.
pre-selected "landmark" stars to serve as reference points.
Guidance Sensors (2)
Hubble precisely locked on its target.
instruments in place.
primary and secondary mirrors in place using special material that
will not expand or contract.
light from space and reflects it to the secondary mirror.
light from the primary mirror and reflects it through a hole in the primary
mirror to the focal plane.
on Hubble Instruments
Objects Camera (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).
Telescope Imaging Spectrograph (STIS)
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.
Field Planetary Camera 2 (WFPC2)
WFPC1 in 1993. . WFPC2 will be replaced by Wide Field Camera 3 in 2003.]
camera takes crystal-clear pictures over a wide field of view and broad
range of wavelengths.
Infrared Camera & Multi-Object Spectrometer (NICMOS) [replaced
Goddard High-Resolution Spectrograph (GHRS)]
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.
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.
State Recorder (2) (one
in use, one spare)
SSR replaced a reel-to-reel, mechanical tape recorder in 1997.]
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
Single Access Transmitter (SSAT) (2)
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.