Space Shuttle Challenger was NASA’s second Space Shuttle orbiter to be put into service, Columbia being the first. Its maiden flight was on April 4, 1983, and it completed nine missions before breaking apart 73 seconds after the launch of its tenth mission, on January 28, 1986, resulting in the death of all seven crew members. The break up was ultimately due to the failure of an O-ring on its right solid-fuel rocket booster (SRB). The failure was due to a variety of factors, including unusually low temperatures prior to liftoff.
The accident led to a two-and-a-half year grounding of the shuttle fleet. The missions resumed in 1988 with the launch of Space Shuttle Discovery.