Ten years ago, on Feb. 1, 2003, the crew of the Space Shuttle Columbia returned to Earth from what had appeared to have been a successful mission to the International Space Station. The launch of the shuttle two weeks earlier, however, caused damage to the spacecraft: A chunk of foam from the orbiter's external fuel tank broke and punched a hole in the shuttle's protective heat shield.
Upon reentry, the heat proved too much for the damaged space shuttle, which exploded in air. All seven members of the crew of STS-107 -- Rick Husband, Willie McCool, Michael Anderson, Kalpana Chawla, David Brown, Laurel Clark and Ilan Ramon -- died.
NASA, which had had a 17-year safety record since the Challenger disaster, blamed complacency for permitting the disaster to occur.