The explosion of the Challenger Space Shuttle was very tragic.  There were seven crew members on board of the Challenger, their names were Mike Smith, Dick Scobee, Ron McNair, Ellison Onizuka, Christina McAuliffe, Gregory Jarvis, and Judith Resnik.

Christina McAuliffe would be the first person in space without NASA training.  Nearly one minute after liftoff the unthinkable happened and the Challenger exploded.  The SRB's (Solid Rocket Boosters) swerved away from the thick cloud of smoke. Not but seconds after the blast, an expanding ball of gas was visible from the shuttle's external tank. The worst disaster in NASA history had happened.