1990 s31 IMAX view of HST release.jpg
Discovery deploys the Hubble Space Telescope.
NamesSpace Transportation System-35
Mission typeHubble Space Telescope deployment
COSPAR ID1990-037A Edit this at Wikidata
SATCAT no.20579
Mission duration5 days, 1 hour, 16 minutes, 6 seconds (achieved)
Distance travelled3,328,466 km (2,068,213 mi)
Orbits completed80
Spacecraft properties
SpacecraftSpace Shuttle Discovery
Launch mass117,586 kg (259,233 lb)
Landing mass85,947 kg (189,481 lb)
Payload mass11,878 kg (26,187 lb)
Crew size5
Start of mission
Launch date24 April 1990, 12:33:51 UTC
RocketSpace Shuttle Discovery
Launch siteKennedy Space Center, LC-39B
ContractorRockwell International
End of mission
Landing date29 April 1990, 13:49:57 UTC
Landing siteEdwards Air Force Base,
Runway 22
Orbital parameters
Reference systemGeocentric orbit
RegimeLow Earth orbit
Perigee altitude613 km (381 mi)
Apogee altitude615 km (382 mi)
Period96.70 minutes
Air Force Maui Optical Site (AMOS)
Ascent Particle Monitor (APM)
IMAX Cargo Bay Camera (ICBC)
In-flight Radiation Dose Distribution (IDRD)
Protein Crystal Growth (PCG)
Radiation Monitoring Equipment III (RME III)
Sts31 flight insignia.png

STS-31 mission patch
Sts-31 crew.jpg

Charles F. Bolden Jr., Steven A. Hawley, Loren J. Shriver, Bruce McCandless II, Kathryn D. Sullivan
← STS-36 (34)
STS-41 (36) →

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

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.

Discovery's crew deployed the Hubble Space Telescope on 25 April 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.


Position Astronaut
Commander Loren J. Shriver
Second spaceflight
Pilot Charles F. Bolden Jr.
Second spaceflight
Mission Specialist 1 Bruce McCandless II
Second and last spaceflight
Mission Specialist 2 Steven A. Hawley
Third spaceflight
Mission Specialist 3 Kathryn D. Sullivan
Second spaceflight

Crew seating arrangements

Seat[1] Launch Landing
Space Shuttle seating plan.svg

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

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.
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
HST in the cargo bay

STS-31 was launched on 24 April 1990 at 8:33:51 a.m. EDT. A launch attempt on 10 April 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 ordered the valve closed 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-infrared wavelengths. 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 also 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 29 April 1990 at 6:49:57 a.m. PDT. 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 7 May 1990.[11]

Attempt Planned Result Turnaround Reason Decision point Weather go (%) Notes
1 10 Apr 1990, 12:00:00 am scrubbed technical  ​(T-4 minutes) Faulty valve in Auxiliary power unit (APU) Number One.[4]
2 24 Apr 1990, 12:33:51 pm delayed, successful 14 days, 12 hours, 34 minutes technical  ​(T-31 seconds) Countdown was held at T-31 seconds 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]

Flight Day Song Artist/Composer
Day 2 "Space is Our World" Private Numbers
Day 3 "Shout" Otis Day and the Knights
Day 4 "Kokomo" Beach Boys
Day 5 "Cosmos" Frank Hayes
Day 6 "Rise and Shine" Raffi


See also


  1. ^ Becker, Joachim. "Spaceflight mission report: STS-31". SPACEFACTS. Archived from the original on 7 January 2021. Retrieved 26 February 2014.
  2. ^ Janson, Bette R.; NASA; Scientific and Technical Information Division (1 March 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. Public Domain This article incorporates text from this source, which is in the public domain.
  3. ^ Carr, Jeffry (17 March 1988). "JSC News Release Log 1988" (PDF). Lyndon B. Johnson Space Center. Houston, Texas: NASA. p. 88-008. Archived (PDF) from the original on 25 February 2017. Public Domain This article incorporates text from this source, which is in the public domain.
  4. ^ a b c Office of Safety, Reliability, Maintainability and Quality Assurance (15 October 1990). "Misson Safety Evaluation Report for STS-31 - Postflight Edition" (PDF). Washington, D.C.: NASA. p. 7-1. Archived (PDF) from the original on 7 January 2021.((cite web)): CS1 maint: multiple names: authors list (link) Public Domain This article incorporates text from this source, which is in the public domain.
  5. ^ Gavaghan, Helen (7 July 1990). "Design flaw cripples Hubble telescope". No. 1724. New Scientist. Archived from the original on 7 January 2021.
  6. ^ @1438322692097286151 (16 September 2021). "" (Tweet). Retrieved 16 September 2021 – via Twitter.((cite web)): CS1 maint: numeric names: authors list (link)
  7. ^ "Camera, ICBC, 70mm, IMAX". National Air and Space Museum. Smithsonian Institution. Archived from the original on 7 January 2021. Retrieved 7 January 2021.
  8. ^ a b c Lyndon B. Johnson Space Center (May 1990). "STS-31 Space Shuttle Mission Report" (PDF). NASA. Archived (PDF) from the original on 7 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  9. ^ Goodman, John L.; Walker, Stephen R. (31 January 2009). Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Technique (PDF). 32nd Annual AAS Guidance and Control Conference. Breckenridge, Colorado: NASA. p. 6. Archived (PDF) from the original on 7 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  10. ^ MacKnight, Nigel (31 December 1991). Space Year 1991: The Complete Record of the Year's Space Events. Osceola, Wisconsin: Motorbooks International. p. 41. ISBN 978-0879384821.
  11. ^ Ryba, Jeanne (23 November 2007). "STS-31". Mission Archives. NASA. Archived from the original on 7 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  12. ^ Fries, Colin (13 March 2015). "Chronology of Wakeup Calls" (PDF). History Division. NASA. Archived (PDF) from the original on 5 January 2021. Retrieved 5 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.