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Space Shuttle Challenger
Space Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first.
Its maiden flight was on April 4, 1983, and itcompleted nine missions before breaking apart 73 seconds after the launch of its tenth mission, STS-51-L on January 28, 1986, resulting in the death of all seven crew members. The accident led to atwo-and-a-half year grounding of the shuttle fleet, with missions resuming in 1988 with the launch of Space Shuttle Discovery on STS-26.
Because of the low production of orbiters, the Space Shuttle programdecided to build a vehicle as a Structural Test Article, STA-099, that could later be converted to a flight vehicle. In order to prevent damage during structural testing, qualification tests wereperformed to a factor of safety of 1.2 times the design limit loads. The qualification tests were used to validate computational models, and compliance with the required 1.4 factor of safety was shown byanalysis.
NASA planned to refit the prototype orbiter Enterprise (OV-101), used for flight testing, as the second operational orbiter. However, design changes made during construction of the firstorbiter, Columbia (OV-102), would have required extensive rework. Because STA-099's qualification testing prevented damage, NASA found that rebuilding STA-099 as OV-099 would be less expensive thanrefitting Enterprise.
Challenger was destroyed as it broke up in mid-flight in the second minute of its tenth mission, on January 28, 1986, at 11:38:00 am Eastern Standard Time. The breakup wasultimately due to the failure of an O-ring on its right solid-fuel rocket booster (SRB). The O-rings are used to seal the joints between the multiple segments of the SRBs. The failure was due to a variety offactors, including unusually low temperatures prior to liftoff
Damage near the bottom of the (ET) external fuel tank resulted in the complete loss of the aft dome of the lower tank and a rapid...