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Mission or Study ID:   STS-41B
Shuttle Program
Launch/Start Date:
Landing/End Date:
8 days
STS-41B Crew patch

STS-41B was the tenth shuttle mission and the forth flight of the Space Shuttle Challenger. The STS-41B crew, Commander Vance D. Brand, Pilot Robert L. Gibson, and Mission Specialists Bruce McCandless II, Ronald E. McNair, and Robert L. Stewart, were originally scheduled to launch on January 29. However, the launch was postponed five days to allow replacement of all three auxiliary power units (APUs), a precautionary measure in response to APU failures during the STS-9 mission.

Among the many payloads flown on STS-41B was the Shuttle Student Involvement Program (SSIP), sponsored jointly by the National Science Teacher's Association and NASA. SSIP gives students in U.S. secondary schools the opportunity to propose experiments for flight on the Space Shuttle. A contest is held every year to select experiments for flight. An individual or organization in the private sector sponsors each experiment. Two corporate sponsors were involved in the STS-41B SSIP experiment because of its complex nature. General Dynamics designed and developed the animal housing unit, and Pfizer, Inc., helped the student investigator define the science aspects of the experiment. The objective of the experiment was to test the hypothesis that development of arthritis has a gravity-related component.

Other payloads flown on STS-41B were five Get-Away-Special canisters flown in the cargo bay, Cinema-360 camera used by the crew, Acoustic Containerless Experiment System (ACES), Monodisperse Latex Reactor (MLR), Radiation Monitoring Equipment (RME), and Isoelectric Focusing (IEF).

STS-41B was the first mission that crewmembers performed untethered spacewalks using the manned maneuvering unit. Other activities performed during the mission were the deployment of two satellites. However, rocket motor failure left both satellites in radical low-Earth orbit. A German-built Shuttle Pallet Satellite (SPAS), first flown on STS-7, became the first satellite to be refurbished and reflown. Although planned for deployment, SPAS remained in the payload by because of an electrical problem with the remote manipulator system.

After successfully completing the STS-41B mission, the Shuttle Challenger landed safely at Kennedy Space Center (KSC) in Florida. This was the first landing of a shuttle at KSC.

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