STS-41-B

STS-41-B

Bruce McCandless demonstrates the MMU, floating in space above a clouded Earth.
Mission type	Satellite deployment Equipment testing
Operator	NASA
Mission duration	7 days, 23 hours, 15 minutes, 55 seconds
Distance travelled	5,329,150 kilometres (3,311,380 mi)
Orbits completed	128
Spacecraft properties
Spacecraft	Space Shuttle Challenger
Launch mass	113,603 kilograms (250,452 lb)
Landing mass	91,280 kilograms (201,238 lb)
Payload mass	22,323 kilograms (49,214 lb)
Start of mission
Launch date	3 February 1984, 13:00:00 (1984-02-03UTC13Z) UTC
Launch site	Kennedy LC-39A
End of mission
Landing date	11 February 1984, 12:15:55 (1984-02-11UTC12:15:56Z) UTC
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee	307 kilometres (166 nmi)
Apogee	317 kilometres (171 nmi)
Inclination	28.5 degrees
Period	90.8 minutes
L-R: Seated, Vance Brand, Commander, Robert Gibson, Pilot. Standing, L-R: Mission Specialists Robert L. Stewart, Ronald McNair and Bruce McCandless. Stewart and McCandless are wearing extravehicular mobility units (EMU). Space Shuttle program ← STS-9 STS-41-C →

STS-41-B was the tenth NASA Space Shuttle mission and the fourth flight of the Space Shuttle Challenger. It launched on 3 February 1984 and landed on 11 February. Following STS-9, the flight numbering system for the Space Shuttle program was changed. Thus, the next flight, instead of being designated STS-11, became STS-41-B; the original successor to STS-9, STS-10, was cancelled due to payload delays.

Crew

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 First spaceflight

Spacewalks

• McCandless and Stewart – EVA 1
• EVA 1 Start: 7 February 1984
• EVA 1 End: 7 February 1984
• Duration: 5 hours, 55 minutes

• McCandless and Stewart – EVA 2
• EVA 2 Start: 9 February 1984
• EVA 2 End: 9 February 1984
• Duration: 6 hours, 17 minutes

Mission summary

Palapa B2 after deployment. Astronaut Bruce McCandless exercises the Manned Maneuvering Unit. McCandless approaches his maximum distance from Challenger.

Challenger lifted off from Kennedy Space Center at 8 am EST on 3 February 1984. Two communications satellites were deployed about 8 hours after launch; one, Westar 6, was for Western Union, and the other, Palapa B2, for Indonesia. However, the Payload Assist Modules (PAM) for both satellites malfunctioned, placing them into a lower-than-planned orbit. Both satellites were retrieved successfully the following November, during STS-51-A, by the orbiter Discovery.

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.

On 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. McCandless, the first human Earth-orbiting satellite, ventured out 320 feet (98 m) from the orbiter, while Stewart tested the "work station" foot restraint at the end of the Remote Manipulator System. On the seventh day of the mission, both astronauts performed an EVA to practice capture procedures for the Solar Maximum Mission satellite retrieval and repair operation, which was planned for the next mission, STS-41-C.

STS 41-B also achieved the reflight of the West German-sponsored SPAS-1 pallet/satellite, which had originally flown on STS-7. This time, however, it remained in the payload bay due to an electrical problem in the RMS. The mission also carried five 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.

The 7-day, 23-hour, 15-minute, 55-second flight ended on 11 February 1984, at 7:15 am EST; at Kennedy Space Center's Shuttle Landing Facility – the first landing of a spacecraft at its launch site. The uncredited landing of STS-41-B is shown at the beginning of the IMAX documentary The Dream is Alive. During STS-41-B, Challenger completed 127 orbits and traveled 2.8 million miles.

Mission insignia

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 Manned Maneuvering Unit.

Wake-up calls

NASA began a tradition of playing music to astronauts during the Gemini program, 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.

Flight Day	Song	Artist/Composer	Played for
Day 2	garbled during broadcast, title unknown	Contraband	Ron McNair
Day 3	"A Train"	Contraband
Day 4	"Glory, Glory, Colorado"	the University of Colorado Band	Vance Brand
Day 5	"Armed Forces Medley"
Day 6	"North Carolina A&T University alma mater" "Southern Mississippi to the Top"		Ron McNair Robert L. Stewart
Day 7	"Theme from The Greatest American Hero"
Day 8	"The Air Force Song"	Air Force CAPCOMs
Day 9	"In the Mood"	Contraband

See also

• List of human spaceflights chronologically
• List of space shuttle missions
• List of spacewalks and moonwalks

References

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

External links

• NASA mission description
• Additional information
• STS-41B video highlights