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Bruce McCandless II demonstrates the Manned Maneuvering Unit (MMU), floating in space above a clouded Earth.
NamesSpace Transportation System-41B
Mission typeCommunications satellites deployment
Equipment testing
COSPAR ID1984-011A Edit this at Wikidata
SATCAT no.14681
Mission duration7 days, 23 hours, 15 minutes, 55 seconds (achieved)
Distance travelled5,329,150 km (3,311,380 mi)
Orbits completed128
Spacecraft properties
SpacecraftSpace Shuttle Challenger
Launch mass113,603 kg (250,452 lb)
Landing mass91,280 kg (201,240 lb)
Payload mass12,815 kg (28,252 lb)[1]
Crew size5
EVA duration12 hours, 12 minutes
First: 5 hours, 55 minutes
Second: 6 hours, 17 minutes
Start of mission
Launch dateFebruary 3, 1984, 13:00:00 UTC
RocketSpace Shuttle Challenger
Launch siteKennedy Space Center, LC-39A
ContractorRockwell International
End of mission
Landing dateFebruary 11, 1984, 12:15:55 UTC
Landing siteKennedy Space Center, Runway 15
Orbital parameters
Reference systemGeocentric orbit[2]
RegimeLow Earth orbit
Perigee altitude307 km (191 mi)
Apogee altitude317 km (197 mi)
Period90.80 minutes
Get Away Special (GAS) canisters

STS-41-B mission patch

Standing: Mission Specialists Robert L. Stewart, Ronald McNair and Bruce McCandless II. Stewart and McCandless are wearing Extravehicular Mobility Units (EMUs).
Seated: Vance D. Brand and Robert L. Gibson
← STS-9
STS-41-C (11) →

STS-41-B was NASA's tenth Space Shuttle mission and the fourth flight of the Space Shuttle Challenger. It launched on February 3, 1984 and landed on February 11, 1984, after deploying two communications satellites. It was also notable for including the first untethered spacewalk.

Following STS-9, the flight numbering system for the Space Shuttle program was changed. Because the original successor to STS-9, STS-10, was canceled due to payload delays, the next flight, originally and internally designated STS-11,[3][4] became STS-41-B as part of the new numbering system.


Position Astronaut
Commander Vance D. Brand
Third spaceflight
Pilot Robert L. Gibson
First spaceflight
Mission Specialist 1 Bruce McCandless II
First spaceflight
Mission Specialist 2 Robert L. Stewart
First spaceflight
Mission Specialist 3 Ronald E. McNair
Only spaceflight


  • Personnel: McCandless and Stewart
  • Date: February 7, 1984
  • Duration: 5 hours, 55 minutes[5]
  • Personnel: McCandless and Stewart
  • Date: February 9, 1984
  • Duration: 6 hours, 17 minutes[5]

Crew seating arrangements[edit]

Seat[6] Launch Landing
Seats 1–4 are on the Flight Deck.

Seats 5–7 are on the Middeck.

S1 Brand Brand
S2 Gibson Gibson
S3 McNair McCandless
S4 Stewart Stewart
S5 McCandless McNair

Mission summary[edit]

STS-41B launch
Palapa B2 after deployment
Astronaut Bruce McCandless exercises the Manned Maneuvering Unit.
McCandless approaches his maximum distance from Challenger.


The STS-41-B crew included commander Vance D. Brand, making his second Shuttle flight; pilot Robert L. Gibson; and mission specialists Bruce McCandless II, Ronald E. McNair, and Robert L. Stewart.

Launch and satellite deployment[edit]

Challenger lifted off from Kennedy Space Center at 08:00:00 a.m. EST on February 3, 1984. It was estimated that 100,000 people attended the launch.[7] Two communications satellites were deployed about 8 hours after launch; one, Westar 6, was for America's Western Union, and the other, Palapa B2, for Indonesia;[8] both were Hughes-built HS-376-series satellites. However, the Payload Assist Modules (PAM) for both satellites malfunctioned, placing them into a lower-than-planned orbit. Both satellites were retrieved successfully in November 1984 during STS-51-A, which was conducted by the orbiter Discovery.[8]

Untethered EVA[edit]

On February 7, the fourth day of the mission, astronauts McCandless and Stewart performed the first untethered spacewalk, operating the Manned Maneuvering Unit (MMU) for the first time.[5][9] At 8:25 a.m. EST, pulsing the MMU's thrusters, McCandless ventured out of Challenger's payload bay, and reached 98 m (322 ft) from the orbiter.[10] Stewart tested the "work station" foot restraint at the end of the Remote Manipulator System (Canadarm).[10] On the seventh day of the mission, both astronauts performed another extravehicular activity (EVA) to practice capture procedures for the Solar Maximum Mission (SMM) satellite retrieval and repair operation, which was planned for the next mission, STS-41-C.[5]

Scientific experiments[edit]

STS-41-B also achieved the reflight of the West German-sponsored SPAS-1 pallet/satellite, which had originally flown on STS-7.[11] This time, however, it remained in the payload bay due to an electrical problem in the RMS (Canadarm). The mission also carried five Get Away Special (GAS) canisters, six live rats in the middeck area, a Cinema-360 camera and a continuation of the Continuous Flow Electrophoresis System and Monodisperse Latex Reactor experiments.[11] Included in one of the GAS canisters was the first experiment designed and built by a high school team to fly in space. The experiment, on seed germination and growth in zero gravity, was created and built by a team of four students from Brighton High School in Utah through a partnership with Utah State University.[11]

Brighton High School STS-11 Decal
Brighton High School STS-11 Decal

Issues with the orbiter[edit]

During the mission, the nozzles of Challenger's supply and wastewater venting systems experienced below-freezing temperatures; subsequently, the supply water dump valve failed to open, so excess water was dumped through the flash evaporator for the remainder of the mission.[12][13]: 6  During re-entry, ice from the dump valves broke off their nozzles situated near the nose of the orbiter and struck the left Orbital Maneuvering System (OMS) pod, damaging three Thermal Protection System (TPS) tiles and leading to a burn-through,[13]: 4  but the damage was minimal enough that Challenger and its crew were unharmed.[3][13]: 19  During the post-flight inspection it was found that the dump line upstream of the two nozzles had ruptured due to the wastewater expanding as it froze, and insulation was missing around both nozzles.[13]: 6, 17  The TPS tiles near the nozzles were also discolored, indicating ice had built up prior to re-entry.[13]: 19 

Return to Earth[edit]

The 7 days, 23 hours, 15 minutes, and 55 seconds flight ended on February 11, 1984 with a successful landing at Kennedy Space Center's Shuttle Landing Facility. This marked the first landing of a spacecraft at its launch site. Challenger completed 128 orbits and traveled 5,329,150 km (3,311,380 mi).

Mission insignia[edit]

Designed by artist Robert McCall, the eleven stars in the blue field symbolize the mission's original designation as STS-11. The left panel shows the deployment of a satellite, and the right panel shows an astronaut using the MMU.

Wake-up calls[edit]

NASA began a tradition of playing music to astronauts during the Project Gemini, and first used music to wake up a flight crew during Apollo 15. Each track is specially chosen, often by the astronauts' families, and usually has a special meaning to an individual member of the crew, or is applicable to their daily activities.[14]

Flight day Song Artist/composer Played for
Day 2 Garbled during the broadcast, title unknown Contraband[a] Ronald E. McNair
Day 3 "A Train" Contraband
Day 4 "Glory, Glory, Colorado"
"Ride High You Mustangs"
The University of Colorado Band
Cal Poly San Luis Obispo / H.P. Davidson[15]
Vance D. Brand
Robert L. Gibson
Day 5 "Armed Forces Medley" Vance D. Brand
Bruce McCandless
Robert L. Gibson
Robert L. Stewart
Day 6 "North Carolina A&T University alma mater"
"Southern Mississippi to the Top"
North Carolina A&T University
University of Southern Mississippi
Ronald E. McNair
Robert L. Stewart
Day 7 "Theme from The Greatest American Hero" Joey Scarbury A planned EVA
Day 8 "The Air Force Song" U.S. Air Force CAPCOMs
Day 9 "In the Mood" Contraband

After the mission[edit]

Astronaut Bruce McCandless II sued singer Dido in 2010 over the use of a public domain photo of him in space on this mission on her 2008 album Safe Trip Home.[16]

Two years after this mission, Ronald E. McNair was a crew member of the ill-fated STS-51-L. He and his six colleagues were killed when Challenger disintegrated 14 km (8.7 mi) above the Atlantic Ocean 73 seconds after liftoff.[17]

See also[edit]


  1. ^ "Contraband" was the name of a music group of NASA employees, among them Ron McNair on the tenor sax.[14]


  1. ^ "NASA shuttle cargo summary" (PDF). NASA. Archived from the original (PDF) on August 31, 2000. Retrieved August 15, 2015. Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ McDowell, Jonathan. "SATCAT". Jonathan's Space Report. Retrieved March 23, 2014.
  3. ^ a b Legler, Robert D.; Bennett, Floyd V. (September 2011). "Space Shuttle Missions Summary" (PDF). Mission Operations Johnson Space Center. p. 2-10. Retrieved December 21, 2023.
  4. ^ Barton, Dick; Cometa, Sue; Gordon, Bob; Green, Bill; Howard, Bob; Schilder, Shirley (January 1984). "41-B Press Information" (PDF). Rockwell International Office of Public Relations. p. 1. Retrieved December 21, 2023.
  5. ^ a b c d "Feb. 7, 1984: NASA Astronauts Perform First Untethered Spacewalk". The New York Times. February 7, 2012. Retrieved July 20, 2013.
  6. ^ "STS-41B". Spacefacts. Retrieved February 26, 2014.
  7. ^ Stanley, Rick (February 4, 1984). "Backed Up Cars; Broken Down Bus; a Beautiful Launch". Florida Today. Cocoa, Florida. p. 3A – via Newspapers.com.
  8. ^ a b ""It'll Be A Miracle": The Rescue of Palapa and Westar (Part 1)". AmericaSpace. November 12, 2012. Retrieved July 28, 2013.
  9. ^ ""More Favored than the Birds": The Manned Maneuvering Unit in Space". NASA. 1998. Retrieved July 20, 2013. Public Domain This article incorporates text from this source, which is in the public domain.
  10. ^ a b Noble, John Wilfred (February 8, 1984). "2 ASTRONAUTS FLOAT FREE IN SPACE, 170 MILES UP". New York Times. pp. A1, B10. Retrieved February 7, 2024.
  11. ^ a b c "STS-41-B". Encyclopedia Astronautica. Archived from the original on April 15, 2002. Retrieved July 20, 2013.
  12. ^ Winkler, H. Eugene (July 1, 1992). Shuttle Orbiter Environmental Control and Life Support System - Flight Experience (PDF). International Conference On Environmental Systems, July 13-16 1992, Seattle, Washington. SAE International. p. 7. doi:10.4271/921348. ISSN 0148-7191 – via SAE Mobilus. On flight STS-41 B in January 1984, during a simultaneous supply and wastewater dump, the temperature of both dump nozzles became very cold, well below freezing. Later in the mission, the supply water dump valve failed to open and excess water had to be dumped through the flash evaporator. After the flight, the dump line near the dump nozzle was found to be ruptured, apparently by ice formation.
  13. ^ a b c d e Collins, Jr., Michael A.; Aldrich, A. D.; Lunney, G.S. (March 1984). "STS-41B National Space Transportation Systems Mission Program Report" (PDF). NASA Technical Reports Server. National Aeronautics and Space Administration - Lyndon B. Johnson Space Center. pp. 4, 6, 17, 19. Retrieved December 21, 2023.
  14. ^ a b Fries, Colin (June 25, 2007). "Chronology of Wakeup Calls" (PDF). NASA. Archived from the original (PDF) on December 20, 2023. Retrieved August 13, 2007. Public Domain This article incorporates text from this source, which is in the public domain.
  15. ^ Cal Poly San Luis Obispo Mustang Band. "Band Handbook - School Songs". Mustang Band - The Pride of the Pacific. Cal Poly University Bands. Retrieved December 21, 2023.
  16. ^ Michael Zhang (October 8, 2010). "NASA Astronaut Sues Dido Over Album Cover Photograph".
  17. ^ "Astronaut Bio: Ronald McNair 12/03". jsc.nasa.gov. Archived from the original on March 21, 2009. Retrieved February 7, 2020. Public Domain This article incorporates text from this source, which is in the public domain.

External links[edit]