STS-41-B

STS-41-B was NASA's tenth Space Shuttle mission and the fourth flight of the Template:OV. 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,<ref name="Shuttle Missions Summary">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name="41-B Press Information">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> became STS-41-B as part of the new numbering system.

Crew

Spacewalks

EVA 1

• Personnel: McCandless and Stewart
• Date: February 7, 1984
• Duration: 5 hours, 55 minutes<ref name=NYT />

EVA 2

• Personnel: McCandless and Stewart
• Date: February 9, 1984
• Duration: 6 hours, 17 minutes<ref name=NYT />

Crew seat assignments

citation	CitationClass=web }}</ref>	Launch	Landing	File:Space Shuttle seating plan.svg Seats 1–4 are on the flight deck. Seats 5–7 are on the mid-deck.
1	Brand
2	Gibson
3	McNair	McCandless
4	Stewart
5	McCandless	McNair
6	Unused
7	Unused

Mission summary

File:STS-41-B Launch (20071535339).jpg

STS-41B launch

File:STS-41-B Palapa B-2 deployment.jpg

Palapa B2 after deployment

File:STS-41-B EVA.jpg

Astronaut Bruce McCandless exercises the Manned Maneuvering Unit.

File:EVAtion - GPN-2000-001087.jpg

McCandless approaches his maximum distance from Challenger.

Crew

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

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.<ref>Template:Cite news</ref> 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;<ref name="AmericaSpace">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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.<ref name="AmericaSpace" />

Untethered EVA

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.<ref name=NYT>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }} Template:PD-notice</ref> At 8:25 a.m. EST, pulsing the MMU's thrusters, McCandless ventured out of ChallengerTemplate:'s payload bay, and reached Template:Cvt from the orbiter.<ref name="MMU to 98 m">Template:Cite news</ref> Stewart tested the "work station" foot restraint at the end of the Remote Manipulator System (Canadarm).<ref name="MMU to 98 m" /> 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.<ref name=NYT />

Scientific experiments

STS-41-B also achieved the reflight of the West German-sponsored SPAS-1 pallet/satellite, which had originally flown on STS-7.<ref name=Ency>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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.<ref name=Ency /> 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.<ref name=Ency />

File:Brighton High School STS-11 Payload Decal.jpg

Brighton High School STS-11 Decal

Issues with the orbiter

During the mission, the nozzles of ChallengerTemplate:'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.<ref>Template:Cite conference</ref><ref name="STS-41B Mission Report" />Template:Rp 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,<ref name="STS-41B Mission Report">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>Template:Rp but the damage was minimal enough that Challenger and its crew were unharmed.<ref name="Shuttle Missions Summary" /><ref name="STS-41B Mission Report" />Template:Rp 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.<ref name="STS-41B Mission Report" />Template:Rp The TPS tiles near the nozzles were also discolored, indicating ice had built up prior to re-entry.<ref name="STS-41B Mission Report" />Template:Rp

Return to Earth

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 Template:Cvt.

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 MMU.

Wake-up calls

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.<ref name="chronology">Template:Cite news Template:PD-notice</ref>

Flight day	Song	Artist/composer	Played for
Day 2	Garbled during the broadcast, title unknown	ContrabandTemplate:Efn	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<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	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

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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

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 Template:Cvt above the Atlantic Ocean 73 seconds after liftoff.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }} Template:PD-notice</ref>

See also

• List of human spaceflights
• List of Space Shuttle missions
• Lists of spacewalks and moonwalks

External links

• Mission summary Template:Webarchive and additional information Template:Webarchive NASA
• STS-41-B Post-flight video summary with crew narration
• NASA Video – Astronaut Bruce McCandless II Floats Free in Space
• Template:NARA catalog record