Following the Challenger accident clarification was required on mission numbering. As STS-51-L was also designated STS-33, future flights with the previous STS-26 through STS-33 designators would require the R in their documentation to avoid conflicts in tracking data from one mission to another.[citation needed]
Discovery's crew deployed the Hubble Space Telescope on April 25, 1990, and then spent the rest of the mission tending to various scientific experiments in the Shuttle's payload bay as well as 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.
Seats 1–4 are on the flight deck. Seats 5–7 are on the mid-deck.
1
Shriver
2
Bolden
3
McCandless
Sullivan
4
Hawley
5
Sullivan
McCandless
6
Unused
7
Unused
Crew notes
This mission was originally to be flown in August 1986 as STS-61-J using Atlantis, but was postponed due to the Challenger disaster. John W. 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 J. 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.Hubble Space Telescope in the cargo bay of Discovery
STS-31 was launched on April 24, 1990 at 12:33:51UTC (8:33:51amEDT, local time at the launch site). A launch attempt on April 10, 1990, 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 manually commanded the valve to close and the countdown continued.[4]
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-infraredwavelengths. The Hubble mission was a joint NASA-ESA (European Space Agency) effort going back to the late 1970s.[5] 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 613 × 615 km (381 × 382 mi). At one point during the mission, Discovery briefly reached an apogee of 621 km (386 mi), the highest altitude ever reached by a Shuttle orbiter.[6] 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.[7] Experiments on the mission 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.[8]Discovery orbited the Earth 80 times during the mission.[8]
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.[8]
The mission marked the flight of an 5 kg (11 lb) 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 Runway 22 at Edwards Air Force Base in California on April 29, 1990, at 13:49:57UTC (6:49:57amPDT, local time at the landing site). The landing had a rollout distance of 2,705 m (8,875 ft), took 61 seconds, and marked the first use of carbon brakes on a shuttle. Discovery was returned to Kennedy Space Center after STS-31 on May 7, 1990.[11]
Countdown was held at T−0:31 when a fuel valve line on ground support equipment failed to shut automatically. The valve was shut manually and the countdown was resumed.[4]
Wake-up calls
NASA began a tradition of playing music to astronauts during the Project Gemini, 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]
^Janson, Bette R. (March 1, 1988). Ritchie, Eleanor H.; Saegesser, Lee D. (eds.). Astronautics and Aeronautics, 1985: A Chronology(PDF). Washington, D.C.: United States Government Printing Office. p. 282. This article incorporates text from this source, which is in the public domain.
^Carr, Jeffry (March 17, 1988). "JSC News Release Log 1988"(PDF). Lyndon B. Johnson Space Center. Houston, Texas: NASA. p. 88-008. Archived(PDF) from the original on February 25, 2017. This article incorporates text from this source, which is in the public domain.
^"Camera, ICBC, 70 mm, IMAX". National Air and Space Museum. Smithsonian Institution. Archived from the original on January 7, 2021. Retrieved January 7, 2021.
^MacKnight, Nigel (December 31, 1991). Space Year 1991: The Complete Record of the Year's Space Events. Osceola, Wisconsin: Motorbooks International. p. 41. ISBN978-0-87938-482-1.
^Ryba, Jeanne (November 23, 2007). "STS-31". Mission Archives. NASA. Archived from the original on January 7, 2021. This article incorporates text from this source, which is in the public domain.
^Fries, Colin (March 13, 2015). "Chronology of Wakeup Calls"(PDF). History Division. NASA. Archived from the original(PDF) on January 5, 2021. Retrieved January 5, 2021. This article incorporates text from this source, which is in the public domain.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).
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