The U-S government is launching at least three investigations to determine what caused the space shuttle Columbia to disintegrate over Texas Saturday, killing all seven astronauts on board.
National Aeronautics and Space Administration chief Sean O'Keefe says nothing has been ruled out. He says NASA, an independent panel of experts and U-S lawmakers will probe every possible angle.
U-S officials say they believe a mechanical problem caused the shuttle to break up just 16 minutes before its scheduled landing at Florida's Kennedy Space Center.
NASA's investigation began immediately after the accident. An independent panel chaired by retired Admiral Harold Gehman is also at work. Admiral Gehman also headed the official investigation into the October 2000 bombing of the destroyer U-S-S Cole.
Congressman Sherwood Boehlert says the science committee he chairs in the U-S House of Representatives also will look into the disaster.
A former chairman of the House committee, Representative James Sensenbrenner, is calling on the Bush Administration to appoint an independent panel to conduct a broader investigation, in much the same manner as the presidential commission that probed the 1986 shuttle Challenger disaster.
Mr. O'Keefe of NASA said the space agency owes it to the families of the crew members to find and fix the problem that caused the accident, and that NASA will let the facts speak for themselves.
Columbia, NASA's oldest shuttle, was returning from a 16-day science flight in Earth orbit when it disintegrated over Texas and Louisiana, raining chunks of debris over hundreds of square kilometers of prairie and wooded terrain.