STS-31

STS-31
NASA/IMAX · Public domain · source
Name	STS-31
Mission type	Satellite deployment
Operator	NASA
Mission duration	5 days, 1 hour, 16 minutes, 6 seconds
Distance travelled	3,328,466 kilometers
Orbits completed	80
Spacecraft	Space Shuttle Discovery
Launch date	April 24, 1990, 12:33:51 UTC
Launch site	Kennedy Space Center, LC-39B
Landing date	April 29, 1990, 13:49:57 UTC
Landing site	Edwards Air Force Base, Runway 22
Insignia caption	Mission patch

STS-31 was the thirty-fifth mission of the NASA Space Shuttle program and the tenth flight of the Space Shuttle ''Discovery''. Its primary objective was the successful deployment of the Hubble Space Telescope, a revolutionary orbiting observatory designed for astronomy free from the distortions of Earth's atmosphere. The mission, launched on April 24, 1990, from Kennedy Space Center, achieved a record-setting orbital altitude for the shuttle program to ensure the telescope's long-term operational life.

Mission highlights

The launch of STS-31 was delayed several times, including a halt at T-4 minutes due to a faulty valve in one of ''Discovery'''s main engines. Once launched, the crew performed a series of engine burns to reach an operational orbit of approximately 612 kilometers, the highest yet achieved by a Space Shuttle. This high orbit was critical to minimize atmospheric drag on the Hubble Space Telescope. The flight plan included extensive checks of the telescope's systems prior to its release from the shuttle's payload bay.

Hubble Space Telescope deployment

On the mission's second day, Steven A. Hawley used the shuttle's Remote Manipulator System to grapple and lift the telescope from the payload bay. After final systems checks, the Hubble Space Telescope was released into space on April 25, 1990. The deployment was broadcast live on television worldwide. Following release, the crew slowly backed Discovery away from the telescope to avoid contamination and performed a final inspection fly-around. Ground controllers at the Goddard Space Flight Center then began the process of activating the observatory's systems.

Crew

The mission was commanded by Loren J. Shriver, with Charles F. Bolden serving as the pilot. The three Mission Specialists were Steven A. Hawley, who operated the robotic arm for the deployment, Bruce McCandless II, a veteran of the first untethered spacewalk using the Manned Maneuvering Unit, and Kathryn D. Sullivan, who would later become the first American woman to perform a spacewalk. Sullivan and McCandless were prepared to conduct an Extra-vehicular activity if mechanical issues had arisen during the telescope's deployment.

Mission parameters

*Mass: **Orbiter liftoff: 116,121 kg **Orbiter landing: 85,947 kg **Payload: 11,878 kg (Hubble Space Telescope) *Perigee: 613 km *Apogee: 615 km *Inclination: 28.5° *Period: 96.7 minutes

Mission background

STS-31 was the culmination of decades of planning by the astronomical community and NASA. The Hubble Space Telescope, named for astronomer Edwin Hubble, was built by Lockheed and Perkin-Elmer, with contributions from the European Space Agency. Its development was plagued by technical delays and budget overruns. The shuttle mission itself was originally scheduled for 1986 but was postponed following the ''Challenger'' disaster. The high orbital altitude selected required Discovery to carry minimal other payloads.

Aftermath and legacy

Shortly after deployment, scientists discovered a flaw in the telescope's primary mirror causing spherical aberration, which severely blurred its initial images. This led to the planning of the first servicing mission, STS-61, in 1993 to correct the optics. Despite this initial setback, STS-31 is celebrated for successfully placing humanity's most significant optical observatory into orbit. The Hubble Space Telescope has since revolutionized astrophysics, providing iconic images and critical data on topics from the age of the universe to exoplanet atmospheres, fulfilling the mission's ultimate promise.

Category:Space Shuttle missions Category:1990 in spaceflight Category:Hubble Space Telescope