Hubble Space Telescope
, named after the American astrophysician
Edwin Powell Hubble
The Hubble Space Telescope (HST) was the first of the Great Observatories
launched, and is exploring our universe in the visible, ultraviolet,
near-infrared regions of our electromagnetic spectrum. It was designed by Lyman
Spitzer and proposed to NASA in the early 60ies. It is maintained by the
first servicing mission:
The second mission occured in Feb 1997 with
The third mission (3A) was in Dec 1999 with
In Feb 1999 it is announced that 3 of the 6 gyroscopes failed and that an
advanced service mission is needed to replace them. On 13 Nov 1999 the
satellite was placed in safe-mode after loosing the 4th gyroscope. The third
was in Dec 1999 with
Hubble received new gyroscopes, a new solid state recorder, an S-band
transmitter, a new onboard computer (486), and several spare components (total
new equipment worth $70 million).
3B service mission
brought a new solar array to replace the one installed during the
first servicing mission
It will provide 5270 W (20% more) but will be be 2/3 of the old ones (reducing
the atmospheric drag). The solar port and the reaction wheel assembly were also
changed. The Power Control Unit was also changed; that required a full shutdown
of the satellite (the unit distributed electricity to all the instruments and
flight systems). They also installed the Advanced Camera for Surveys (ACS)
which replaced the last original instrument, the Faint Object Camera. ACS will
give astronomers 10 times the optical power they've had so far using Hubble's
Wide Field-Planetary Camera. The last spacewalk was to install an electronic
support module for a new experimental cooling device for the Near-Infrared
Camera ans Multi-Object Spectrometer (NICMOS).
On 3 Aug 2004, the STIS payload failed, probably a power converter failure.
This payload was added by the second servicing mission.
On 1st Sep 2005, HST started operating with 2 gyros only in order to preserve
the 3rd one, and extend its science operations through mid-2008.
The Advanced Camera for Surveys (ACS) was suspended on 19 Jun 2006 due to a
power problem. It was reactivated with the backup power supply in late June.
More problems occured on 23 Sep 2006 and on 27 Jan 2007, related to the power
supply to the ACS.
On 27 Sep 2008, a computer failure occured which interrupted science data flow
and delayed the 4th servicing mission. A switch to backup back plane (Side B)
was launched on 15 Oct 2008. The satellite could be recovered fully in
The 4th servicing Mission brougth Two new instruments: the Cosmic Origins
Spectrograph (COS) and the Wide Field Camera 3 (WFC3). The COS is the most
sensitive ultraviolet spectrograph ever flown on Hubble. WFC3 is a new camera
sensitive across a wide range of wavelengths, including infrared, visible, and
ultraviolet light. Two existing instruments need fixing -- the Advanced Camera
for Surveys (ACS) and the Space Telescope Imaging Spectrograph (STIS). Other
changes will be made (batteries, gyros, etc.).
Cost: $3 billion (not including the STS service missions)
Perkin Elmer (mirror & telescope)
x 2.83 m
Data acquisition via
Telemetry: 2287.5 MHz (500 bps, 4 kbps, 32 kbps)
Command: 2106 MHz (1/0.125 kbps)
Data: 2255.5 MHz (1024 kbps)
visible and near IR
Wide-Field Planetary Camera, Faint Object Camera (ESA), Faint Object
Spectrograph, High Resolution Spectrograph, High Speed Photometer
The WFPC 2 replaced the original camera on 1st servicing mission and Costar
replaced the High Speed Photometer
On the second servicing mission, the Space Telescope Imaging Spectrograph
replaced both GHRS (the Goddard High Res Spectrograph) and FOS (the Faint
Object Spectrograph). NICMOS, the Near Infrared Camera and Multi-Object
Spectrometer was added to overs the 0.8 to 2.5 micron spectral range.