51-l

STS-51-L was the 25th mission of NASA's Space Shuttle program and the final flight of Space Shuttle Challenger.
Planned as the first Teacher in Space Project flight in addition to observing Halley's Comet for six days and performing a routine satellite deployment, the mission never achieved orbit; a structural failure during its ascent phase 73 seconds after launch from Kennedy Space Center Launch Complex 39B on January 28, 1986, killed all seven crew members —Commander Francis R. "Dick" Scobee, Pilot Michael J. Smith, Mission Specialists Ellison S. Onizuka, Judith A. Resnik and Ronald E. McNair, and Payload Specialists Gregory B. Jarvis and S. Christa McAuliffe—and destroyed the orbiter.
Immediately after the disaster, President Ronald Reagan convened the Rogers Commission to determine the cause of the explosion. The failure of an O-ring seal on the starboard Solid Rocket Booster (SRB) was determined to have caused the shuttle to break up in flight. Space Shuttle flights were suspended while the O-rings and other hazards that could have destroyed the vehicle on following missions were addressed. Shuttle missions resumed in September 1988 with STS-26, launched 32 months after the accident.

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