The space shuttle Challenger explosion was a defining moment of the 1980s. Whether you were watching on TV or in person, chances are, you remember exactly where you were and how you felt.

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

Seven astronauts lost their lives during the Challenger space shuttle disaster on Jan. 28, 1986. Four decades later, human ...

TODAY marks four decades since the Challenger space shuttle exploded just 73 seconds into its flight. Millions watched the disaster unfold live, as the tragedy was broadcast in schools and on TV ...

The Space Shuttle Challenger disaster on January 28, 1986, killed all seven astronauts on board, but disturbing details later ...

On Jan. 28, 1986, the Space Shuttle Challenger exploded 73 seconds after takeoff. All seven crew members on board were killed ...

Forty years after the space shuttle Challenger disintegrated shortly after liftoff, the disaster remains one of the most consequential tragedies in U.S. spaceflight history.

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

The Space Shuttle Columbia disaster saw the spacecraft disintegrate during re-entry into Earth's atmosphere, killing all seven crew members in a tragic and preventable incident ...

Jan. 28, 1986, 7 spacefarers were killed when shuttle Challenger exploded midair after launching from Kennedy Space Center in ...

On Jan. 28, 1986, the Space Shuttle Challenger exploded 73 seconds after takeoff. All seven crewmembers on board were killed.

(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.