Hubble Space Telescope

Hubble Space Telescope (HST), the first large optical orbiting observatory . Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble ) was expected to provide the clearest view yet obtained of the universe. Using a Ritchey-Chrétien design that affords wider and flatter fields of view than traditional Cassegrain systems, the telescope has a 7.9-ft (2.4-m) primary mirror that can observe 24 hours a day (but usually observes less than 20% of the time) in a sky that is always clear and always has perfect seeing . Among the instruments are two high-resolution cameras and two spectrographs. The HST was launched from shuttle Atlantis in 1990. Initial tests taken after its launch showed that the primary mirror was astigmatic, and it was discovered that the mirror had been mistakenly ground to the wrong figure. The telescope was repaired by astronauts of the space shuttle Endeavour in Dec., 1993, who replaced critical instruments and added corrective optics while in orbit. Subsequent servicing missions in 1997 and 1999 added capabilities to HST, which observes the universe at ultraviolet, near-ultraviolet, visible, and near-infrared wavelengths. In Mar., 2002, astronauts from the space shuttle Columbia made repairs and improvements designed to enable the observatory to function for another decade, but in 2004 the power supply for the ultraviolet spectrograph failed.

Hubble Space Telescope (HST) Optical telescope that was placed in Earth orbit by the space shuttle in 1990. Images transmitted back to Earth revealed that the telescope's main mirror was incorrectly shaped. A repair team corrected the fault in 1993, and it was again repaired in 1997. Hubble now produces acurate images of bodies that cannot be observed clearly by terrestrial telescopes due to atmospheric distortion.

http://www.stsci.edu

Hubble Space Telescope (HST) A 2.4-m reflector built by NASA and ESA, launched in 1990April. It orbits at an altitude of about 600 km. An initial servicing mission by astronauts in 1993December was necessary to install additional optics to correct the telescope's spherical aberration, caused by an error in manufacturing the main mirror. Subsequent servicing missions took place in 1997February, 1999December, and 2002March, during which astronauts installed improved detectors and replaced the telescope's solar panels. After the fourth servicing mission, HST's scientific instruments consisted of the Advanced Camera for Surveys (ACS), the Wide Field and Planetary Camera 2 (WFPC2), the Near Infrared Camera and Multi–Object Spectrometer (NICMOS), and the Space Telescope Imaging Spectrograph (STIS). A fifth and final servicing mission is planned for 2008 to install the Cosmic Origins Spectrograph (COS) and the Wide Field Camera 3 (WFC3). HST is controlled from NASA's Goddard Space Flight Center. The Space Telescope Science Institute plans the telescope's observing programme and collects its data. European access to the HST is managed by the Space Telescope European Coordinating Facility (ST-ECF) in Garching, Germany. http://www.nasa.gov/mission_pages/hubble/main/index.html