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NASA Releases Columbia Crew Survival Report
Migraineman writes "NASA has released a 400-page Columbia Crew Survival Investigation Report [16MB PDF.] If you're interested in a detailed examination and timeline of the events leading to the destruction of Columbia, this is well worth the time. The report includes a number of recommendations to increase survivability of future missions." Reader bezking points out CNN's story on the report, which says that problems with the astronauts' restraint systems were the ultimate cause of death for the seven astronauts on board.
They knew all that mostly from a video of the re-entry taken seconds before the shuttle disintegrated. They didn't piece it together from the wreckage (apart from finding the video tape in the wreckage).
The report lists the immediate causes of death as depressurization, and then trauma (not properly restrained, or failure of restraint for upper body and head in sudden depressurization) for those who survived even that long.
Each event listed after is in of itself certain death, and the report makes sure to say that even if everyone were wearing their full equipment and had been properly restrained, there was no way to survive - there simply isn't a way for our current equipment to "eject" or have a "safety capsule."
The things we can take away are that all signs point to sudden, painless deaths well before breakup, and that the things learned in the investigation can be applied for greater safety in future missions.
Actually the cause of death may have been the trauma, or it may have been the rapid depressurization preceding that. The report wasn't able to determine which was the actual cause.
On a positive note however, at least it seems the depressurization knocked them unconscious quick enough that they didn't suffer much.
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In April 2008 a Soyuz made an uncontrolled reentry due to failure of the service module to separate during the de-orbit sequence. The cosmonauts survived due to the inherent ballistic stability and fail-safety of the design:
http://www.spectrum.ieee.org/may08/6229
NASA has finally conceded that the safest place for the astronauts is on top of the launch stack, with abort rockets to escape a failing lower stage, and with no exposure to damage from falling debris. These factors plus the increased safety of ballistic reentry explain the return to capsules with the Constellation system.
Shuttle vs. Soyuz Reliability
http://forum.nasaspaceflight.com/index.php?topic=7954.0
Soyuz vs Shuttle
http://salul.wordpress.com/2008/09/25/soyuz-vs-shuttle/
I believe the actual cause of anyone's death when suddenly exposed to the extreme thin (lack of) atmosphere at high altitudes, is extreme forceful asphyxiation.
At 30,000 feet MSL, the healthiest humans can only maintain consciousness about 1.5 minutes max.
At 35,000 feet MSL you'll last only about half as long... 45 seconds max.
At 40,000 feet MSL, after rapid decompression, you might stay conscious for 25 seconds if you're in excellent shape.
Remember the Payne Stewart LearJet crash? They lost cabin pressure and the plane on autopilot went up into the flight level 40's.
Above 50,000 feet you must wear a pressure suit in addition to breathing supplemental oxygen... unless you're inside a pressurized aircraft/spacecraft.
At 63,000 feet MSL, all the gases dissolved in your blood boils. You die in seconds if exposed to rapid decompression.
The Columbia began it's breakup around 200,000 feet MSL and most educated guestimates place the altitude where the pressurized crew compartment broke away from the rest of the craft at around 100,000 feet and that it held its pressure until about 60,000 feet until it broke open.
The ballistic trajectory of the big chunks of what was left of the ship took a sharp downward turn once it reached about 40,000 feet MSL due to all the pieces slowing down so rapidly and then fracturing into such small pieces as to next be more accurately called a debris cloud in the relatively thick atmosphere of 35,000 feet compared to where the breakup first began.... at least that's what the math models derived from the shape and size of the debris field on the ground seems to suggest.
One thing that always amazes me, and that most people don't even understand is that the actual atmospheric air pressure difference between here on the ground and being in the "vacuum" of space, is only 14.7 teeny-tiny pounds per square inch.
That's right. Less than 15 measly PSI. Fifteen PSI ain't even enough air in your car tire to make it roll very well. And that's all the difference there is between ground and space. Space is not some huge gigantic super vacuum that'll crush a strong metal container as if it was a beer can. Space is actually a quite subtle difference in pressure from what we breath here on the surface, especially when you compare it the pressure difference to what you'd find a only a few thousand feet under the sea.
Capsules don't rely on tiles but instead use single-ablative shields that are protected during the entire flight until reentry.
After each launch the shuttle has to be completely rebuilt so there weren't any cost savings.
A little more about problems with the shuttle design by a Nobel-Prize winning physicist....
http://www.fotuva.org/feynman/challenger-appendix.html
love is just extroverted narcissism