At 11:39 a.m. EST on 28 January 1986, the space shuttle Challenger exploded 73 seconds into flight, killing all seven crew members.
One crew member was a civilian, 37-year-old New Hampshire high school social studies teacher, Christa McAuliffe.
President Reagan had been slated to give his State of the Union address that evening. Instead, he spoke to the nation about the disaster from the Oval Office.
In late January 1986, the typical low temperature in Florida would have been 50°F (10°C). Instead, the overnight forecast was 18°F (−8°C). Temperatures near the launch pad were in the 20s mere hours before liftoff. This was the coldest attempted launch of a space shuttle.
A presidential commission determined that the disaster was caused by the failure of an O-ring seal in one of the two solid-fuel rockets. Because of the cold temperature at launch, a chain of events resulted in the explosion.
In 1976, NASA had unveiled Enterprise, the world’s first reusable manned spacecraft. Five years later, Columbia traveled into space on its maiden mission, a 54-hour event.