On Feb. 1, 2003, space shuttle Columbia broke up as it returned to Earth, killing the seven astronauts on board. NASA suspended space shuttle flights for more than two years as it investigated the disaster.
An investigation board determined that a large piece of foam fell from the shuttle's external tank and breached the spacecraft wing. This problem with foam had been known for years, and NASA came under intense scrutiny in Congress and in the media for allowing the situation to continue.
The Columbia mission was the second space shuttle disaster after Challenger, which saw a catastrophic failure during launch in 1986. The Columbia disaster directly led to the retirement of the space shuttle fleet in 2011; NASA is developing a successor commercial crew program that will bring astronauts to the space station no earlier than 2018.
