STS-31

STS-31

Discovery deploys the Hubble Space Telescope
Mission type	Satellite deployment
Operator	NASA
COSPAR ID	1990-037A
SATCAT no.	20579
Mission duration	5 days, 1 hour, 16 minutes, 6 seconds
Distance travelled	3,328,466 kilometers (2,068,213 mi)
Orbits completed	80
Spacecraft properties
Spacecraft	Space Shuttle Discovery
Launch mass	117,586 kilograms (259,233 lb)
Landing mass	85,947 kilograms (189,481 lb)
Payload mass	11,878 kilograms (26,187 lb)
Crew
Crew size	5
Members	Loren J. Shriver Charles F. Bolden Jr. Bruce McCandless II Steven A. Hawley Kathryn D. Sullivan
Start of mission
Launch date	24 April 1990, 12:33:51 (1990-04-24UTC12:33:51Z) UTC
Launch site	Kennedy LC-39B
End of mission
Landing date	29 April 1990, 13:49:57 (1990-04-29UTC13:49:58Z) UTC
Landing site	Edwards Runway 22
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee altitude	613 kilometres (381 mi)
Apogee altitude	615 kilometres (382 mi)
Inclination	28.45 degrees
Period	96.7 minutes
Left to right: Bolden, Hawley, Shriver, McCandless, Sullivan Space Shuttle program ← STS-36 STS-41 →

STS-31 was the 35th mission of the American Space Shuttle program, which deployed the Hubble Space Telescope into Earth orbit. The mission used the Space Shuttle Discovery (the tenth for this orbiter), which lifted off from Launch Complex 39B on 24 April 1990 from Kennedy Space Center, Florida.

Discovery's crew deployed the Hubble 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[]

Crew seating arrangements[]

Seat[1]	Launch	Landing	Seats 1–4 are on the Flight Deck. Seats 5–7 are on the Middeck.
S1	Shriver	Shriver
S2	Bolden	Bolden
S3	McCandless	Sullivan
S4	Hawley	Hawley
S5	Sullivan	McCandless

Crew notes[]

Initially, this mission was to be flown in August 1986 as STS-61J using Atlantis, but was postponed by the Challenger disaster. John Young was originally assigned to command this mission,^[2] which would have been his seventh spaceflight, but was reassigned to an administrative position and was replaced by Loren Shriver in 1988.^[3]

Mission highlights[]

Space Shuttle Discovery launches from LC-39B for STS-31 with Columbia on LC-39A in preparation for STS-35.

HST in the cargo bay.

STS-31 was launched on 24 April 1990 at 8:33:51 am EDT. A launch attempt on 10 April was scrubbed at T-4 minutes for a faulty valve in auxiliary power unit (APU) number one. The APU was eventually replaced and the Hubble Space Telescope's batteries were recharged. On launch day, the countdown was briefly halted at T-31 seconds when Discovery's computers failed to shut down a fuel valve line on ground support equipment. Engineers ordered the valve closed and the countdown continued.^[4]

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 highest orbit up to that date, in order for HST to be released near its operational altitude well outside the atmosphere. Discovery orbited the Earth 80 times during the mission.^[5]

The main purpose of this mission was to deploy Hubble. It was designed to operate above the Earth's turbulent and obscuring atmosphere to observe celestial objects at ultraviolet, visible and near-infrared wavelengths. The Hubble mission was a joint NASA-ESA effort going back to the late 1970s.^[6] The rest of the mission was devoted to photography and onboard experiments. To launch HST into an orbit that guaranteed longevity, Discovery entered an orbit of around 613km by 615km. At one point during the mission, Discovery briefly reached an apogee of 621 kilometres (386 mi), the highest altitude ever reached by a Shuttle orbiter.^[7] The record height also 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 1994 IMAX film Destiny in Space.^[8] Experiments included a biomedical technology study, advanced materials research, particle contamination and ionizing radiation measurements, and a 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 minutes and 58 seconds, the longest in Shuttle history up to that time.^[5]

During the deployment of Hubble, one of the observatory's solar arrays stopped as it unfurled. While ground controllers searched for a way to command HST to unreel the solar array, Mission Specialists McCandless and Sullivan began preparing for a contingency spacewalk in the event that the array could not be deployed through ground control. The array eventually came free and unfurled through ground control, while McCandless and Sullivan were pre-breathing inside the partially depressurized airlock.^[9]

Secondary payloads included the IMAX Cargo Bay Camera (ICBC) to document operations outside the crew cabin and a handheld IMAX camera for use inside the orbiter. Also included were the Ascent Particle Monitor (APM) to detect particulate matter in the payload bay; a Protein Crystal Growth (PCG) experiment to provide data on growing protein crystals in microgravity, Radiation Monitoring Equipment III (RME III) to measure gamma ray levels in the crew cabin; Investigations into Polymer Membrane Processing (IPMP) to determine porosity control in the microgravity environment, and an Air Force Maui Optical Site (AMOS) experiment.^[5]

The mission marked the flight of an 11-pound human skull, which served as the primary element of "Detailed Secondary Objective 469", also known as the In-flight Radiation Dose Distribution (IDRD) experiment. This joint NASA/DoD experiment was designed to examine the penetration of radiation into the human cranium during spaceflight. The female skull was seated in a plastic matrix, representative of tissue, and sliced into ten layers. Hundreds of thermo-luminescent dosimeters were mounted in the skull's layers to record radiation levels at multiple depths. This experiment, which also flew on STS-28 and STS-36, was located in the shuttle's mid-deck lockers on all three flights, recording radiation levels at different orbital inclinations.^[10]

Discovery landed on 29 April 1990 at 6:49:57 am PDT, landing on Runway 22 at Edwards Air Force Base in California. The rollout distance was 2,705 metres (8,875 ft) and took 61 seconds. This also marked the first use of carbon brakes. Discovery returned to KSC on 7 May 1990.^[11]

Wake-up calls[]

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.^[12]

Gallery[]

• 

  Hubble at the pad.

• 

  Liftoff of Discovery with the Hubble Space Telescope on board.

• 

  Low hover position.

• 

  High over Cuba.

• 

  Solar array deployment.

• 

  Hubble drifts away over Peru.

• 

  Florida and the Bahamas.

• 

  Discovery returns home.

See also[]

• List of human spaceflights
• List of Space Shuttle missions
• Outline of space science
• Space Shuttle

References[]

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

External links[]

Wikimedia Commons has media related to STS-31.

• NASA mission summary
• STS-31 Video Highlights