Which space shuttle broke apart shortly after launch in 1986?

The space shuttle that broke apart shortly after launch in 1986 was Challenger. On January 28, 1986, Challenger disintegrated 73 seconds after liftoff during mission STS-51-L, killing all seven crew members.

The disaster began with the failure of an O-ring seal in a joint on the right solid rocket booster. Unusually cold temperatures stiffened the rubber seal, allowing hot gases to escape shortly after launch. The leaking gases damaged the external fuel tank and caused the shuttle stack to break apart under aerodynamic forces.

The crew included commander Dick Scobee, pilot Michael Smith, four mission specialists, and Christa McAuliffe, a teacher selected for NASA's Teacher in Space program. Her presence brought enormous public attention to the launch, which many schoolchildren watched live.

A common mix-up is confusing Challenger with Columbia. Challenger was lost in 1986 during launch; Columbia was destroyed during reentry in 2003. The accident led to a lengthy shuttle program suspension and the construction of Endeavour as a replacement.