January 28th, 1986 at 11:39am EDT - The Space Shuttle Challenger Explodes on its 10th flight during mission STS-51-L. The explosion occurred 73 seconds after liftoff and was actually the result of rapid deceleration and not combustion of fuel.
CNN was the only national news station to broadcast the mission live, so thus what you are witnessing on this video is the only coverage of the disaster as it happened when it did. Approximately 17% of Americans witnessed the launch live, while 85% of Americans heard of the news within 1 hour of the event. According to a study, only 2 other times in history up to that point had news of an event disseminated so fast - the first being the announcement of JFK's assassination in 1963, the second being news spread among students at Kent State regarding the news of FDR's death in 1945. It has been estimated at the time that nearly 48% of 9-13 year olds witnessed the event in their classrooms, as McAuliffe was in the spotlight.
The 25th Space Shuttle mission altered the history of manned space exploration and represented the first loss of an American crew during a space mission (Apollo 1 was during a training exercise).
Christa McAuliffe was slated to be the first teacher in space for the Teacher in Space Program. As her maximum altitude was ~65,000ft (12.31 miles), she never made it to space. That title was given to Barbara Morgan of STS-118 aboard the shuttle Endeavour in August 2007, 22 and a half years after the Challenger Disaster. Morgan served as McAuliffe's backup during STS-51-L. As Morgan is now part of the Educator in Space Program, she will be credited as the first "educator" in space, to distinguish her from McAuliffe.
Aboard Challenger during STS-51-L:
Francis "Dick" Scobee (Commander)
Michael Smith (Pilot)
Judith Resnik (Mission Specialist)
Ellison Onizuka (Mission Specialist)
Ronald McNair (Mission Specialist)
Gregory Jarvis (Payload Specialist)
Sharon Christa McAuliffe (Payload Specialist - Teacher in Space)