Space Shuttle

Scores of shuttle missions were successfully carried out between the Challenger's successful 1988 mission and February 1, 2003, when disaster struck again. The space shuttle Columbia broke up suddenly during reentry, strewing debris over much of Texas and several other states and killing all seven astronauts on board. At the time of this writing, analysts identified that the most likely cause of the loss of the spacecraft related to some form of damage to the outer protective layer of heat-resistant tiles or seals that protect the shuttle's interior from the 3,000°F (1,650°C) plasma (superheated gas) that envelops it during reentry. As described earlier, a coating of rigid foam insulation is The space shuttle Discovery being moved by crawler to the top of pad 39B at the Kennedy Space Center. U.S. National Aeronautics and Space Administration (NASA).
used to keep the external fuel tank cool; video cameras recording the Columbia's takeoff show that a piece of this foam broke off 80 seconds into the flight and burst against the shuttle's wing at some 510 MPH (821 km/h). Pieces of foam have broken off and struck shuttles during takeoff before, but this was the largest piece ever—at least 2.7 lb (1.2 kg) and the size of a briefcase. While Columbia was in orbit NASA engineers, who were aware that the foam strike had occurred, analyzed the possibility that it might have caused significant damage to the shuttle, but decided that it could not have: computer simulations seemed to show that the brittle tiles covering the shuttle's essential surfaces would not be severely damaged. In any event, there were no contingency procedures to fix any such damage. The shuttle does not carry spare tiles or means to attach them, nor does it carry gear that would make a space-walk to the bottom of the shuttle feasible. NSAS officials also insisted that it would not have been possible to fly the shuttle in such a way as to spare the damage surfaces, as the shuttle's path is already designed to minimize heating on reentry. Later testing revealed that the foam impact on the wing was forceful enough to puncture the wing.

Regardless of the exact reason, the shuttle's skin was breached, whether by mechanical damage or some other cause, and hot gasses formed a hot jet that caused considerable damage to the left wing from inside. During reentry, the wing began to break up, experiencing greatly increased drag. The autopilot struggled to compensate by firing steering rockets, but could only stabilize the shuttle temporarily.

As of July 2003, the loss of the Columbia has, like the loss of the Challenger in 1986, put a temporary stop to all shuttle launches. A moratorium on shuttle launches will also have an impact on the International Space Station, which depends on the shuttle to bring it the fuel it needs to stay in orbit and which cannot be completed without components that only the space shuttle can carry. In the wake of the Columbia disaster, NASA and other governmental officials, worked with an independent panel's review of the accident and sought technical improvements to the STS program that might prevent future problems while, at the same time. Returning the remaining shuttles to flight status as soon as safely possible.