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STS-31 crew monitors Hubble Space Telescope (HST) from OV-103's flight deck

Credit: NASA. 56,223 bytes. 576 x 440 pixels.

Class: Astronomy. Type: Visible. Nation: United States. Agency: NASA, MSFC. Manufacturer: Lockheed.

The Hubble Space Telescope is the visible/ultraviolet/near-infrared element of the Great Observatories astronomical program. The spacecraft provides an order of magnitude better resolution than is capable from ground-based telescopes. The objectives of the HST are to: (1) investigate the composition, physical characteristics, and dynamics of celestial bodies; (2) examine the formation, structure, and evolution of stars and galaxies; (3) study the history and evolution of the universe; and (4) provide a long-term space-based research facility for optical astronomy. During initial on-orbit checkout of the Hubble's systems, a flaw in the telescope's main reflective mirror was found that prevented perfect focus of the incoming light. This flaw was caused by the incorrect adjustment of a testing device used in building the mirror. Fortunately, however, Hubble was designed for regular on-orbit maintenance by Shuttle missions. The first servicing mission, STS-61 in December 1993, fully corrected the problem by installing a corrective optics package and upgraded instruments (as well as replacing other satellite components). A second servicing mission, scheduled for March 1997, will install two new instruments in the observatory. Additional servicing missions are planned for 1999, 2002 and 2005. The program includes significant participation by ESA, which provided one of the science instruments, the solar arrays, and some operational support to the program. Responsibility for conducting and co-ordinating the science operations of the Hubble Space Telescope rests with the Space Telescope Science Institute (STScI) at Johns Hopkins University, who operates it for NASA as a general observer facility available to astronomers from all countries.

STS-31STS-31 - Hubble Space Telescope (HST) above OV-103's PLB during STS-31 deployment

Credit: NASA. 71,484 bytes. 626 x 440 pixels.

Spacecraft: 3-Axis stabilised, zero momentum biased control system using reaction wheels with a pointing accuracy of 0.007 arc-sec. Two double-roll-out solar arrays (2.3 m x 12 m) generate 5000 W. Six 60 Ahr batteries. Hydrazine propulsion system. S-band telecom system using deployed articulated HGAs provides uplink at 1 kbps and downlink (via TDRSS) at 256-512 kbps. Payload: Optics: The telescope is an f/24 Ritchey-Chretien Cassegrainian system with a 2.4 m diameter primary mirror and a 0.3 m Zerodur secondary. The effective focal length is 57.6m. The Corrective Optics Space Telescope Axial Replacement (COSTAR) package is a corrective optics package designed to optically correct the effects of the primary mirror's aberration on the Faint Object Camera (FOC), Faint Object Spectrograph (FOS), and the Goddard High Resolution Spectrograph (GHRS). COSTAR displaced the High Speed Photometer during the first servicing mission to HST. Instruments: The Wide Field Planetary Camera (JPL) consists of four cameras that are used for general astronomical observations from far-UV to near-IR. The Faint Object Camera (ESA) uses cumulative exposures to study faint objects. The Faint Object Spectrograph (FOS) is used to analyse the properties of celestial objects such as chemical composition and abundances, temperature, radial velocity, rotational velocity, and magnetic fields. The FOS is sensitive from 1150 Angstroms (UV) through 8000 Angstroms (near-IR). The Goddard High Resolution Spectrometer (GHRS) separates incoming light into its spectral components so that the composition, temperature, motion, and other chemical and physical properties of objects can be analysed. The HRS is sensitive between 1050 and 3200 Angstroms.

STS-31STS-31 - STS-31 Hubble Space Telescope (HST) (SA & HGA deployed) is grappled by RMS

Credit: NASA. 53,542 bytes. 487 x 476 pixels.


Design Life: 15 years (with on-orbit servicing). Total Length: 13.3 m. Maximum Diameter: 4.3 m. Total Mass: 10,863 kg.

HST Chronology

24 April 1990 HST Hubble Space Telescope Launch Site: Cape Canaveral . Launch Vehicle: Shuttle. Mass: 10,863 kg. Perigee: 590 km. Apogee: 596 km. Inclination: 28.5 deg.

Hubble Space Telescope; deployed from STS-31 4/25/90. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B).

STS-31STS-31 - STS-31 Hubble Space Telescope (HST) drifts away from OV-103's RMS

Credit: NASA. 56,135 bytes. 409 x 473 pixels.


STS-31STS-31 - STS-31 Hubble Space Telescope (HST) is released by RMS over Andes Mountains

Credit: NASA. 67,297 bytes. 483 x 475 pixels.

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Last update 12 March 2001.
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© Mark Wade, 2001 .