THE NATION Last moments aboard the Columbia
A NASA report details when the seven shuttle astronauts probably died and lists several equipment failures.
Even though parts of the report were redacted to protect the astronauts' families, it represents the most graphic and harrowing account of the crew's final moments.
Fixing the deficiencies would not have saved the astronauts because the accident -- occurring at high altitude and hypersonic speed -- was "unsurvivable," the report said. But such corrections could improve chances of survival in less serious accidents.
Other design flaws with seat belts, helmets and parachutes also could have caused their deaths if they had survived the depressurization and intense buffeting, the panel said in its final report on the incident.
Poor design of their pressure suits led the seven astronauts aboard the Columbia space shuttle to black out almost immediately as the craft started breaking apart during reentry in 2003, and they were probably killed by the violent contortions, a NASA panel said Tuesday.
NASA officials already knew the astronauts had died from either a lack of oxygen or from striking objects in the cabin, and the report was unable to distinguish between the two possibilities. But it does catalog all the things known to have gone wrong and provide new details about the crash.
One comforting conclusion in the 400-page report is that, after the first few seconds, the astronauts were probably unconscious and never knew what was happening.
"On behalf of their colleagues and families, I can say that we are relieved that we discovered this," astronaut Pamela Melroy, deputy project manager for the investigative team, said at a news conference.
The mission was doomed when a piece of foam broke off the external fuel tank during launch on Jan. 16, 2003, and damaged the leading edge of Columbia's wing. The wing was not inspected because the prevailing belief was that foam could not cause significant damage.
On its reentry to Earth's atmosphere on Feb. 1, Columbia broke up over Texas, killing all seven astronauts.
A 2003 report angrily blamed the accident on a "broken safety culture" at NASA.
The new report said the first problem crew members encountered was their pressure suits, which were not part of the shuttle's original equipment. They were added after the 1986 Challenger disaster.
Because of design problems with the suits, crew members could not keep the visors of their helmets down throughout reentry because it led to high oxygen concentrations in the cabin. And wearing the suit's gloves made it difficult or impossible to perform many tasks.
At the time of the accident, three crew members were not wearing gloves, one did not have his helmet on, and none had the visors down.
The report said the crew members immediately lost consciousness from depressurization.
But "the crew was doing everything they had been trained to do and were doing everything right," Melroy said.
NASA has since made astronauts seal their pressure suits earlier in the reentry, she said.
As the cabin began its wild gyrations during descent, the astronauts were protected only by lap belts. The upper-body belts did not hold them in place because the inertial locks, such as those on car seat belts, were not designed for such sideways motion. The astronauts were thrown around violently.
The contortions were exacerbated by the helmets on the pressure suits, which did not conform to the astronauts' heads and offered no protection from impacts.
The breakup of the cabin exposed the crew to heat and abrupt deceleration caused by friction from the atmosphere. The report said "all crew were deceased before, or by the end of," the breakup.
The remains of the shuttle
NASA has issued a report on survivability during the Space Shuttle ''Columbia'' disaster, entitled "Columbia Crew Survival Investigation Report".  Although the report finds the accident was impossible to survive, it still faulted a number of design issues with the astronauts' equipment.

The accident investigation report was released in 2003, the year of the crash.  During launch on January 16, the spacecraft's wing was holed when a chunk of foam detached and struck it.  The shuttle then broke up on re-entry on February 1 over Texas, killing the seven on board.

This new report reveals details of what happened to the astronauts during the accident sequence, although some parts have remained confidential to the victims' families. The report reveals that within seconds of the breakup commencing the crew became unconscious due to the rapid depressurization and that they never regained consciousness prior to their deaths.

The report notes that the cabin began spinning wildly, causing some of the astronauts' helmets to come off.  The report noted that most on board were secured only by lap harnesses that offered no restraint to the upper body and were not designed to cope with sideways motion, meaning "lethal trauma" was caused by the rotation.  However, the report was unable to determine whether the astronauts had died from oxygen deprivation or the extreme nature of their injuries.
The shuttle's crew
The pressure suits the crew wore, introduced after the Space Shuttle Challenger disaster, were criticised as the crew could not keep their visors down throughout re-entry due to a design limitation that would have caused excess levels of oxygen to be present had they done so, leaving the suits unsealed.  The gloves also made many tasks difficult or impossible.  When the accident occurred, three people were not wearing gloves, one was not wearing a helmet, and none had their visors down.  The helmets also did not conform to the heads of the wearers.

Upon disintegration, the occupants were exposed to extreme heat and high friction from re-entry.  The astronauts likely died very quickly, and were probably dead by the time ''Columbia'' broke apart. 

The report added that although the crew all wore parachutes, they had to be activated by the crew — impossible as they were unconscious.  The report concluded that future spacecraft require sturdier construction and better restraints, while safety devices should be automatic.  NASA is designing better suits and helmets.