O'Keefe described the commission as "an independent objective board'' and said Gehman would be arriving in Shreveport, La., with a team on Sunday afternoon.

"We're going to find out what led to this, retrace all the events ... and leave absolutely no stone unturned in that process,'' O'Keefe said.

On Saturday, O'Keefe said the independent panel would include experts from the Air Force and Navy -- which had five of the seven Columbia crew members _ while officials from the Transportation Department and other federal agencies would study the accident.

At least three government investigations will look into the Columbia.

Gehman was commander in chief of U.S. Joint Forces Command until his retirement in the summer of 2000. Crouch is a former commander of U.S. Army Europe and chief of NATO's Allied Land Forces Central Europe. In that capacity he was commander of the U.S.-led NATO peacekeeping force in Bosnia in 1996-97.

The Cole was refueling in Aden harbor in Yemen on Oct. 12, 2000, when a small boat sidled up to the 505-foot destroyer and detonated a load of explosives. The blast ripped a hole 40 feet high and 40 feet wide in the hull of the $1 billion warship and killed 17 sailors.

It was the first time terrorists had successfully attacked a U.S. Navy ship, and the Cole commission said in its report in January 2001 that the bombers had found a ``seam in the fabric'' of the Navy's system of self-protection. The commission urged improved anti-terrorism training, better intelligence and a recognition that terrorism is a pervasive threat.

"We do believe that this threat is enduring, it's dangerous, people are dying from it, it is not a transitory threat, it's not going away,'' Gehman said in releasing the report.

The Columbia investigations will review all the information NASA collected as the spaceship began its descent, then started breaking up more than 200,000 feet over Texas.

That includes transmissions from the crew, as well as records from the shuttle's sensors, analysis of the debris and data from military, government and commercial satellites.

In addition to the Gehman commission, NASA will conduct its own investigation, as will the House Science Committee, whose chairman is Rep. Sherwood Boehlert, R-N.Y. His committee oversees NASA.

"We're going to get together and fix this problem. We're going to launch shuttles again,'' NASA shuttle project manager Ron Dittemore said.

Boehlert said he is confident the expert panel would find the cause of the disaster.

Military satellites with infrared detectors picked up several flashes as Columbia broke apart, according to a defense official who spoke only on condition of anonymity. It was unclear whether those ``spikes'' of heat indicated an explosion, the burning of pieces of debris re-entering the atmosphere or something else.

O'Keefe and other senior administration officials said there was no indication that any kind of attack from the ground caused the disaster. FBI spokeswoman Angela Bell also said there was no indication of terrorism and that the FBI would have a minor role in the investigation, mainly helping collect evidence.

Following the 1986 explosion of the space shuttle Challenger, President Reagan appointed a 13-member commission headed by former Secretary of State William P. Rogers to investigate the accident.

That commission reported four months later that an O-ring seal leaked in the right booster rocket. That allowed hot gases to burn through the bracket securing the booster to the shuttle, rupturing the shuttle tank.

The shuttle fleet was grounded for nearly three years while changes were instituted and repairs made.