On the 33rd anniversary of the Space Shuttle Challenger disaster, we remember the 7 crew members killed. We take a look back at Peter Jennings' reporting on the explosion on January 28, 1986. | Good Morning America

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,

It's been 40 years since NASA's Challenger disaster. The space shuttle exploded 73 seconds after take-off, killing all seven astronauts on board including teacher Christa McAuliffe. The tragedy unfolded live on television. Investigators later blamed an O-ring that failed in the freezing launch conditions at Cape Canaveral, Florida. #challenger #spaceshuttle #spacetravel #nasa #capecanaveral | 7NEWS Sydney

40 years ago this morning, the unthinkable happened: the Space Shuttle Challenger exploded 73 seconds after liftoff, killing all 7 astronauts on board, including Christa McAuliffe, who was supposed to be the first teacher in space. School children watched in horror as the tragedy happened. This is original coverage from the Eyewitness News vault. | ABC7NY

On January 28, 1986, the NASA space shuttle Challenger exploded 73 seconds after lift-off from Cape Canaveral, killing all seven crew members. It has been called the worst moment in the history of the American space program. #9News | 9 News

"It is the worst disaster in the history of the American space program." Forty years ago on January 28, 1986, the space shuttle Challenger exploded 73 seconds after liftoff from Cape Canaveral, killing all seven crew members, including school teacher Christa McAuliffe from New Hampshire, who had won a national competition to become the first teacher in space. Peter Jennings anchored ABC's World News Tonight from Washington, with John Quiñones leading off the broadcast's coverage. | ABC World New