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Hubble Space Telescope, named after the American astrophysician Edwin Powell Hubble


Designation 20580 / 90037B
Launch date 24 Apr 1990
Country of origin United States
Operator NASA
Mission Scientific: astronomy
Perigee/Apogee 589/598 km
Inclination 28.5°
Period 96 min
Launch vehicle STS 31R

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 Shuttle: first servicing mission: STS 61. The second mission occured in Feb 1997 with STS 82. The third mission (3A) was in Dec 1999 with STS 103.

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 STS 103 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).

The 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 late-October.

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.).

In 2016, the science operations contract was extended by 5 years.

On 5 Oct 2018 the satellite went into safe mode after a gyroscope failure. A backup gyroscope was activated and science usage resumend on 26 Oct 2018.

On 8 Jan 2019 the Wide Field Camera 3 shutdown, but was recovered on 17 Jan 2019. Incorrect voltage measurement caused the issue.

On 13 Jun 2021 the payload computer halted which caused the science instruments to go into safe mode. After switching to backup hardware (notably the Power Control Unit and the Command Unit/Science Data Formatter (CU/SDF)) the satellite returned to service on 18 July.

In late Oct 2021 an issue with synchronisation messages led to payload going offline. full science operations was restored in December 2021.

Cost: $3 billion (not including the STS service missions)

External resources


sat-index articles

Technical data


Prime contractor Lockheed (spacecraft)
Perkin Elmer (mirror & telescope)
Mass at launch 11250 kg
Diameter 4.25 m
Height 13.1 m
Solar array 12 x 2.83 m
Stabilization 3-axis
DC power BOL: 5500 W
Design lifetime 15 years

Data acquisition via TDRS
Telemetry: 2287.5 MHz (500 bps, 4 kbps, 32 kbps)
Command: 2106 MHz (1/0.125 kbps)
Data: 2255.5 MHz (1024 kbps)


Primary mirror diameter 2.4 m
Primary mirror mass 800 kg
Frequency bands UV, visible and near IR
Resolution 0.1 arcsecs
Pointing stability 0.007 arcsecs

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.

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