After the disaster, rescue teams worked day and night.
Challenger disaster: Investigators concluded that the disaster was caused by an O-ring seal failure in a solid-rocket-booster joint, made worse by unusually cold temperatures.
The Challenger disaster killed all seven crew members and shocked the nation.
January 28 marks the anniversary of the Space Shuttle Challenger disaster. In 1986, Challenger broke apart 73 seconds after liftoff from Kennedy Space Center.
