The 1986 Challenger disaster flight was identified by the mission code STS-51-L. Challenger launched on January 28, 1986, from Kennedy Space Center's Launch Complex 39B and broke apart 73 seconds after liftoff, killing all seven crew members.
STS-51-L was the 25th mission of NASA's Space Shuttle program and Challenger's final flight. Its crew included Commander Francis Scobee, Pilot Michael Smith, mission specialists Ellison Onizuka, Judith Resnik, and Ronald McNair, plus payload specialists Gregory Jarvis and Christa McAuliffe, who was selected for NASA's Teacher in Space project.
The Rogers Commission determined that a failure of an O-ring seal in the right solid rocket booster allowed hot gases to escape; unusually cold launch conditions contributed to the failure. The accident halted shuttle launches for nearly three years. A common mix-up is STS-26, which was Discovery's 1988 return-to-flight mission after Challenger, not the disaster flight itself.