2003 – Space Shuttle Columbia disintegrated during the reentry of mission STS-107 into the Earth's atmosphere, killing all seven astronauts aboard.
Columbia was the second of two Space Shuttle missions to end in disaster, after the loss of
Challenger and crew in 1986. The mission, designated STS-107, was the twenty-eighth flight for the orbiter, the 113th flight of the Space Shuttle fleet and the 88th after the
Challenger disaster. It was dedicated to research in various fields, mainly on board the SpaceHab module inside the shuttle's payload bay. During launch, a piece of the insulating foam broke off from the Space Shuttle external tank and struck the thermal protection system tiles on the orbiter's left wing. Similar foam shedding had occurred during previous Space Shuttle launches, causing damage that ranged from minor to near-catastrophic, but some engineers suspected that the damage to
Columbia was more serious. Before reentry, NASA managers limited the investigation, reasoning that the crew could not have fixed the problem if it had been confirmed. When
Columbia reentered the atmosphere of Earth, the damage allowed hot atmospheric gases to penetrate the heat shield and destroy the internal wing structure, which caused the orbiter to become unstable and break apart. After the disaster, Space Shuttle flight operations were suspended for more than two years, as they had been after the Challenger disaster. Construction of the International Space Station (ISS) was paused until flights resumed in July 2005 with STS-114. NASA made several technical and organizational changes to subsequent missions, including adding an on-orbit inspection to determine how well the orbiter's thermal protection system (TPS) had endured the ascent, and keeping designated rescue missions ready in case irreparable damage was found. Except for one mission to repair the Hubble Space Telescope, subsequent Space Shuttle missions were flown only to the ISS to allow the crew to use it as a haven if damage to the orbiter prevented safe reentry. The remaining three orbiters were retired after the building of the ISS was completed.