Challenger Crew's Last Walk

This is the last time these crew members would walk on Earth. Absolutely chilling.

Everyone knows what the Challenger Explosion is, which makes this photo all the more chilling. The crew included social studies teacher Christa McAuliffe, who was awarded the trip through the NASA Teacher in Space Program. She was the first non-military citizen to go to space, but the excitement was short-lived. 73 seconds after lift-off, the spacecraft failed and plunged into the ocean, killing all those on board.