Forty years ago, the NASA space shuttle Challenger exploded 73 seconds after liftoff, killing all seven crew members. Among the seven crew members were five NASA astronauts, as well as a payload ...

Forty years ago, the NASA space shuttle Challenger exploded 73 seconds after liftoff, killing all 7 crew members. Among the seven crew members were 5 NASA astronauts, as well as a payload specialist ...

(CNN) - Wednesday marks the 40th anniversary of the Challenger space shuttle explosion. It was a moment of collective grief on Jan. 28, 1986, when the space shuttle exploded during a live broadcast.

Forty years ago, the world watched in horror as NASA's space shuttle Challenger exploded mid-air, killing all seven crew members aboard. The disaster occurred at what was then the pinnacle of the U.S.