Nearly six years after the tragic loss of the space shuttle Columbia, a new report has concluded that its seven crew members were exposed to five events they could not have survived as the shuttle disintegrated upon re-entry.
The 400-page report released by NASA on Tuesday, takes an in-depth look at the conditions the astronauts faced on Feb. 1, 2003.
The Columbia had sustained damage on liftoff at the start of its mission, when a small amount of foam separated from an external fuel tank and struck the shuttle's left wing. The impact put a small hole in the leading edge of the wing, which ultimately caused the shuttle to break apart when it attempted to return to Earth at the end of its mission.
All seven astronauts onboard the Columbia -- commander Rick Husband, pilot William McCool, Michael Anderson, David Brown, Kalpana Chawla, Laurel Clark and Israeli astronaut Ilan Ramon -- were killed.
The Columbia Crew Survival Investigation Report scrutinizes the Columbia's final moments and names five events "with lethal potential" that the astronauts then faced.
Crew module depressurization
The first lethal event faced by Columbia crew members was the depressurization of the crew module.
As the astronauts prepared for re-entry, they were wearing helmets with their visors tipped up. They were not allowed to keep them closed inside the cabin for technical reasons.
Additionally, one astronaut did not even have a helmet on at the time of re-entry and three astronauts were not wearing gloves, the report said.
NASA believes the astronauts had about 40 seconds to react to what was going on before depressurization took hold.
But the resulting depressurization happened so quickly that there was no time for the astronauts to pull down their visors and the astronauts were left unprotected.
Although some of the astronauts may have been conscious for a few moments, it was not possible for any of them to regain consciousness as the shuttle fell to Earth, the report said.
The report said spacesuits need to be fully operational at the time of re-entry and that built-in survival systems should not rely on manual activation.
Inadequate restraint and helmet protection
The second lethal event related to the forces the astronauts were exposed to as the shuttle lost control.
As the shuttle started to tear apart, the portion containing the astronauts began to rotate.
At this point, after both the astronauts had lost consciousness and depressurization had occurred, the seat restraints failed to lock -- because they were not designed to lock in the specific conditions the shuttle had been exposed to. And it left the astronauts crashing around the inside of their cabin.
As a result, "the unconscious or deceased crew members were exposed to cyclical rotational motion while their upper bodies were inadequately restrained. Helmets that did not conform to the head and the lack of upper body restraint resulted in injuries and lethal trauma," the report said.
The report also recommended that helmets and restraints be designed to operate in a wider variety of scenarios then at present.
Separation from seats and crew module
Intensive forces tore the crew module apart and the crew could not be saved.
The "resultant exposure of the crew to entry conditions" is an event that is not very well understood, the report said.
What is agreed to, by the report authors, is that "all crew were deceased before, or by the end of, this event."
The report said all aspects of crew survival systems must be examined for weaknesses and that shuttle engineers should consider the ways shuttles -- and their component parts -- break apart when designing future spacecraft.
In all cases, structures and systems should be designed "to enhance chances for crew survival," the report said.
But it also acknowledged that "there is no known complete protection from the breakup event except to prevent is occurrence."
Exposure to other extremes
A fourth lethal event was the exposure the astronauts faced to "near vacuum, aerodynamic accelerations, and cold temperatures."
Similar to the forces that tore the shuttle -- and the crew module where the astronauts were situated -- apart, it is difficult for NASA to know how to fix this problem.
The future goal, the report said, should be to make spacesuits as strong as possible to "increase the probability of survival through this type of event."
Ground impact
At the time that the Columbia disintegrated, part of the shuttle was equipped with a parachute system that was deployed manually.
While a parachute would not have saved the Columbia crew, the report recommends that future shuttles be designed with similar survival systems that are not manually-activated.
With files from The Associated Press
