what was the cause of the space shuttle columbia disaster
Space Shuttle Columbia disaster About 82 seconds after launch from Kennedy Space Center's LC-39-A, a suitcase-sized piece of foam broke off from the External Tank (ET), striking Columbia's left wing reinforced carbon-carbon (RCC) panels. As demonstrated by ground experiments conducted by the Columbia Accident Investigation Board, this likely created a 6-to-10-inch (15 to 25 cm) diameter hole, allowing hot gases to enter the wing when Columbia later re-entered the atmosphere. At the time of the foam strike, the orbiter was at an altitude of about 66,000 feet (20 km; 12.5 mi), traveling at Mach 2.46 (1,626 miles per hour or 727 meters per second).