The NASA space shuttle Challenger exploded 40 years ago, on January 28, 1986, just 73 seconds after liftoff. The disaster claimed the lives of all seven astronauts aboard, including Christa McAuliffe, a teacher from New Hampshire who would have been the first civilian in space. “The crew of the space shuttle Challenger honored us by the manner in which they lived their lives,” President Regan said in an address to the nation that night. “We will never forget them, nor the last time we saw them,

On the 40th anniversary of the Challenger explosion, 60 Minutes revisits a 1996 interview with engineers who said they tried to stop the launch. The space shuttle broke apart shortly after liftoff, killing all seven crew members, including teacher Christa McAuliffe. | 60 Minutes