On February 1, 2003, the space shuttle Columbia was reentering Earth's atmosphere after a two-week routine mission when it exploded, killing all seven astronauts aboard and scattering debris across multiple states. It was a horrific tragedy, particularly considering that the shuttle was on its 28th mission and had been a solid vehicle for space exploration and research since the 1980s. What happened to the space shuttle Columbia effectively ended NASA's shuttle program. In 2011, NASA's space shuttle fleet was officially retired.