Remembering the Challenger explosion, 40 years later

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

She trained to be 1st teacher in space. 40 years later, her mission lives on

Christa McAuliffe trained to be the first teacher in space, preparing to turn a shuttle cabin into the most-watched classroom in America. Forty years after she and six crewmates died when Challenger ...