This Day in History:, Challenger Disaster.
January 28, 1986.
73 seconds after its 11:38 a.m.
Launch, NASA's space shuttle exploded, killing all seven crew members.
Among the crew was Christa McAuliffe, a 37-year-old high school social studies teacher from New Hampshire.
McAuliffe had won a competition that earned her a place on the Challenger.
Millions witnessed the tragedy on live television.
In the aftermath, President Ronald Reagan appointed a special commission to determine what went wrong with Challenger.
The investigation determined the disaster was caused by the failure of an “O-ring” seal due to cold weather.
It would be two years before NASA sent astronauts into space again