Forty years ago, Americans were shocked when the space shuttle Challenger exploded 73 seconds after it launched on a chilly day in Florida.

NASA's space shuttle Challenger completed 10 missions before it broke apart during a launch in 1986, killing seven astronauts.

Former astronaut and professor Terry Hart is opening up 40 years later about the friends and colleagues he lost on board the space shuttle Challenger explosion.

Seven American spacefarers were killed in a tragic event 40 years ago today that has become widely known as the Challenger disaster.

Families of the astronauts lost in the space shuttle Challenger accident gathered back at the launch site Thursday to mark that tragic day 40 years ago.

Wednesday marked 40 years since the space shuttle Challenger accident that killed seven crew members. The mission was not just to launch satellites but to launch the first teacher in space.

On Jan. 28, 1986, America witnessed a tragedy: the explosion of Space Shuttle Challenger in the blue skies over Florida. The doomed shuttle touched us like we have never been touched before because along with the tragic loss of astronauts, a teacher was on board.