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STS-31
Mission insignia
Mission statistics
Mission name	STS-31
Space shuttle	Discovery
Launch pad	39B
Launch date	24 April 1990, 12:33:51 UTC
Landing	29 April 1990, 13:49:57 UTC
Mission duration	5/01:16:6
Number of orbits	80
Orbital altitude	330 nautical miles (610 km; 380 mi)
Orbital inclination	28.45 degrees
Distance traveled	3,328,466 kilometres (2,068,213 mi)
Crew photo
Related missions
Previous Subsequent STS-36 STS-41

STS-31 was the thirty-fifth mission of the American Space Shuttle program, which launched the Hubble Space Telescope astronomical observatory into Earth orbit. The mission used the Space Shuttle Discovery, which lifted off from Launch Pad 39B on 24 April 1990 from Kennedy Space Center, Florida.

Discovery's crew deployed the telescope on 25 April, and spent the rest of the mission tending to various scientific experiments in the shuttle's payload bay and operating a set of IMAX cameras to record the mission. Discovery's launch marked the first time since January 1986 that two Space Shuttles had been on the launch pad at the same time – Discovery on 39B and Columbia on 39A.

Crew[link]

Crew Notes[link]

Initially, this mission was to be flown in August 1986 as STS-61-J using Atlantis, but was postponed due to the Challenger disaster. John Young was originally assigned to command this mission, which would have been his seventh spaceflight, but was reassigned to an administrative position and was replaced by Loren Shriver.

Mission parameters[link]

• Mass:
  • Orbiter Liftoff: 117,586 kilograms (259,230 lb)
  • Orbiter Landing: 85,947 kilograms (189,480 lb)
  • Payload: 11,878 kilograms (26,190 lb)
• Perigee: 585 kilometres (364 mi)
• Apogee: 615 kilometres (382 mi)
• Inclination: 28.5°
• Period: 96.7 min

Mission highlights[link]

Space Shuttle Discovery races into the sky at the start of STS-31, whilst, for the first time since 1986, a second shuttle, Columbia, waits for her chance to launch.

HST in the cargo bay.

Hubble released during deployment.

Launched 24 April 1990, 8:33:51 am EDT. Launch scheduled for 18 April, then 12 April, then 10 April, following Flight Readiness Review (FRR). First time date set at FRR was earlier than that shown on previous planning schedules. Launch 10 April scrubbed at T-4 minutes due to faulty valve in auxiliary power unit (APU) number one. APU replaced and payload batteries recharged. Countdown briefly halted at T-31 seconds when computer software failed to shut down a fuel valve line on ground support equipment. Engineers ordered valve to shut and countdown continued. Launch Weight: 112,994 kilograms (249,110 lb).

STS-31 was the tenth launch of the Shuttle Discovery. On board were Charles Bolden, Loren Shriver, Bruce McCandless, Steven Hawley, and Kathryn D. Sullivan.

The primary payload was the Hubble Space Telescope (HST), deployed in a 380 statute mile (612 kilometres (380 mi)) orbit. The shuttle's orbit in this mission was its second highest orbit up to that date, in order that the HST could be released near to its operational altitude well outside of the atmosphere. Discovery orbited the earth 80 times during the mission.

The main purpose of this mission was to deploy the Hubble Space Telescope (HST) astronomical observatory. It was designed to operate above the Earth's turbulent and obscuring atmosphere to observe celestial objects at ultraviolet, visible and near-infrared wavelengths. This was a joint NASA-ESA effort. The rest of the mission was devoted to photography and onboard experiments. To launch HST into an orbit that guaranteed longevity, Discovery soared to 600 kilometres (370 mi) – the highest shuttle altitude ever at the time. The record height permitted the crew to photograph earth's large scale geographic features not apparent from lower orbits. Motion pictures were recorded by two IMAX cameras, and the results appeared in the IMAX film Destiny in Space. Experiment activity included a biomedical technology study, advanced materials research; particle contamination and ionizing radiation measurements; and student science project studying zero gravity effects on electronic arcs. Discovery’s reentry from its higher than usual orbit required a deorbit burn of 4 min 58 s, the longest in shuttle history up to that time.

Secondary payloads: IMAX Cargo Bay Camera (ICBC) to document operations outside crew cabin and hand-held IMAX camera for use inside crew cabin; Ascent Particle Monitor (APM) to detect particulate matter in payload bay; Protein Crystal Growth (PCG) to provide data on growing protein crystals in microgravity; Radiation Monitoring Equipment III (RME III) to measure gamma ray levels in crew cabin; Investigations into Polymer Membrane Processing (IPMP) to determine porosity control in microgravity environment; Shuttle Student involvement program (SSIP) experiment to study effects of near-weightlessness on electrical arcs, and Air Force Maui Optical Site (AMOS) experiment.

29 April 1990, 6:49:57 am PDT, Runway 22, Edwards Air Force Base, CA. Rollout distance: 2,705 metres (8,875 ft). Rollout time: 61 seconds. First use of carbon brakes at landing. Orbiter returned to KSC on 7 May 1990. Landing Weight: 85,782 kilograms (189,120 lb).

Wake-up calls[link]

NASA began a tradition of playing music to astronauts during the Gemini program, which was first used to wake up a flight crew during Apollo 15. Each track is specially chosen, often by their families, and usually has a special meaning to an individual member of the crew, or is applicable to their daily activities.^[2]

Gallery[link]

• 

  Hubble at the pad.

• 

  Liftoff of the Space Telescope.

• 

  Low hover position.

• 

  High over Cuba.

• 

  Solar array deployment.

• 

  Hubble drifts away over Peru.

• 

  Florida and the Bahamas.

• 

  Discovery returns home.

See also[link]

Spaceflight portal

• Space science
• Space shuttle
• List of space shuttle missions
• List of human spaceflights chronologically

References[link]

This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. Please help to improve this article by introducing more precise citations. (August 2009)

 This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.

External links[link]

• NASA mission summary
• STS-31 Video Highlights