What went wrong?

The article explores the reasons behind the accident of the Columbia space shuttl leading to the death of its crew of seven members. About 80 seconds into the flight, a briefcase-sized chunk of foam insulation with a mass of just over a kilogram broke away from the shuttle's giant external fuel tank and collided with Columbia's left wing, shattering into a white cloud. NASA knew that an almost identical incident with Columbia in 1992 had gouged a hole in the heat-shield tiles less than 3 centimetres deep and about dozen centimetres long, but had not penetrated the protective layer. The Columbia scientific mission proceeded without incident until re-entry. Everything went wrong suddenly. The Columbia's flight control system detected excessive drag on the left side of the vehicle and began to compensate using the elevons flight-control surfaces on the rear of the delta wings unusually by firing two small thruster jets. There was also an unusual temperature rise inside the craft allowing the plasma to invade the craft leading to the accident.