On February 1, 2003, the Space Shuttle Columbia disintegrated upon reentering Earth's atmosphere, killing all seven crew members. The disaster was the second fatal accident in the Space Shuttle program after Space Shuttle Challenger, which broke apart and killed the seven-member crew 73 seconds after liftoff in 1986.
During the launch of STS-107, Columbia's 28th mission, a piece of foam insulation broke off from the Space Shuttle external tank and struck the left wing of the orbiter. A few previous shuttle launches had seen damage ranging from minor to nearly catastrophic from foam shedding, but some engineers suspected that the damage to Columbia was more serious. NASA managers limited the investigation, reasoning that the crew could not have fixed the problem if it had been confirmed. When Columbia re-entered the atmosphere of Earth, the damage allowed hot atmospheric gases to penetrate the heat shield and destroy the internal wing structure, which caused the spacecraft 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.