NASA yesterday named a retired Navy admiral to lead an independent investigation into the incident, which took the lives of all seven crew members on board.
The remains of all seven astronauts who were killed in the space shuttle Columbia tragedy have been recovered, US officials said last night.
The confirmation came from the Johnson Space Centre in Houston as it emerged that the US space shuttle programme has been postponed indefinitely by the National Aeronautics and Space Administration (NASA) following the disintegration of Columbia on re-entry into the Earth's atmosphere on Saturday morning.
Throughout yesterday, residents of Texas and Louisiana stumbled upon fragments of the craft and human remains scattered across a swathe of mostly rural land 10 miles wide and 100 miles long.
Services of commemoration took place in Washington and other cities for the astronauts, who were 15 minutes away from a 9.15 a.m. touchdown at Cape Kennedy, Florida, at the end of a 16-day scientific expedition.
President Bush will travel to Houston, home of the US space centre, for a memorial service tomorrow.
The shuttle was travelling at 18 times the speed of sound, 39 miles above Texas, when disaster struck.
Speculation on the cause of the break-up has centred on heat-resistant tiles on the under-section of the craft, as the incident occurred at the exact moment when the heat of re-entry was at its maximum.
During lift-off on January 16th, a piece of spray-on foam insulation detached from the shuttle's liquid-fuel tank. NASA engineers believed it hit the left wing but that it did not cause enough damage to prevent a successful re-entry - though even if it had, there was no way to repair the craft.
It is also possible that there was an explosion of fuels and oxidizers, or that the craft buckled as it re-entered the Earth's atmosphere.
Minutes before the craft disintegrated, mission control in Houston lost data from hydraulic sensors in the left wing's control flaps and from temperature and pressure sensors in the left landing gear's wheel-well and brake-line.
Temperatures on Columbia rose as the space shuttle hurtled across the United States and disintegrated as it entered the atmosphere to land, NASA officials said yesterday. But even up to the loss of radio contact with the seven crew, ground controllers did not believe the shuttle was experiencing serious problems, NASA space shuttle programe director Mr Ron Dittemore told a press briefing. He also said there was no evidence that the crew knew what was happening.
Mr Dittemore said temperatures shot up on the left hand side of Columbia in the seven minutes before the radio went dead.
The rise was most marked -- 60 degrees Fahrenheit (15.5 Celsius) - on the mid-fuselage and particularly around the left wheel well as Columbia crossed California.
The independent inquiry, led by retired Navy admiral Mr Harold W. Gehmen, will sift through the Columbia wreckage being collected and transported to Barksdale Air Force Base in Louisiana.
FBI agents are also assisting in the recovery, but officials emphasised that there was no evidence of sabotage. NASA will conduct its own investigation, and Senate and House committees will conduct separate inquiries.
The loss of the shuttle, one of four in NASA's fleet, casts a shadow over the US space programme, coming as it does when defence costs are soaring over homeland security and war preparations in the Persian Gulf.
The 2004 US budget that Mr Bush was scheduled to unveil today was to include a NASA initiative, called Project Prometheus, to develop systems to enable human crews to venture beyond Earth's orbit for the first time in three decades.
Much of the debris from Columbia, including circuit boards and a space helmet, was found scattered over the town of Nacogdoches and surrounding pine forests. One piece of tile fell within 75 miles of President Bush's ranch in Crawford, Texas.
In Hemphill Hospital, employee Mr Mike Gibbs came across a "pretty gruesome" find that he said appeared to be a charred torso, thigh-bone and skull. On a farm in Sabine County, two boys found a charred human leg.
Makeshift memorials were erected around debris scattered throughout east Texas, where the Houston Chronicle reported that souvenir hunters were pocketing pieces of the spacecraft that may provide clues about Columbia's disintegration, and that some landowners were refusing to let authorities on their land where debris had fallen.
Despite warnings that the debris could be toxic, some 78 people went to three Texas hospitals for check-ups after touching bits of the shuttle they had come across.
No one was injured by falling debris, although a grey chunk crashed 10 feet from one man.