Re: msnbc.com (Oberg): Space crew (Soyuz) weathers a scare during re-entry
- From: Pat Flannery <flanner@xxxxxxxxxx>
- Date: Mon, 17 Oct 2005 14:22:45 -0500
Jim Oberg wrote:
Note historical background at end of story:
Ever since I first read of the problems with sealing the descent module hatch on Soyuz 11, I've been more than a little suspicious of the official explanation of how that accident occurred.
James Oberg already knows this- but for those who don't, the official explanation was that after a failure of the primary explosive bolt separation system between the descent and orbital modules of the Soyuz, the secondary explosive bolt system was used. But its detonation caused the primary system to also fire simultaneously, and the shock of both systems firing at once caused a pressure valve in the descent module (designed to allow pressure equalization to occur after reentry between the capsule's interior and the outside atmosphere as it approached landing) to open up while the capsule was still in space- so that the crew quickly suffocated.
The official explanation let ground control off the hook for giving the crew the okay to separate from Salyut 1 and begin their reentry, despite the fact that they had problems sealing the hatch, and finally got the "hatch open" light to go out only by over-tightening the hatch latching system beyond its specified limit.
The explosive bolts are located a few feet from the pressure equalization valve (located under the cosmonaut's seats), but only a few inches from the descent module's hatch...a hatch that was already behaving in an abnormal manner.
If the faulty descent module hatch had sprung a leak due to the stress of the explosive bolts firing, pressure in the descent module would rapidly drop to zero; and since the pressure inside the descent module and outside of it would now be equal (zero) this could cause the pressure equalization valve to open.
Such a scenario would not be unknown for the Soviet Union by any means- the managers of the Chernobyl reactor assured Moscow that the reactor itself was intact for over a day after the accident, despite the fact that there were blocks of graphite and control rods scattered all over the vicinity of the blast.
Years earlier, a Voskhod undergoing tests had its jettisonable airlock detach by accident and fall to the assembly room floor, leaving it irreparably damaged. In that case the facility managers stated that the accident was due to CIA sabotage rather than incompetence on their own part.
In this most recent Soyuz problem, you can see a similarity in the way the Russian mission control reacted to the way they did during the Soyuz 11 flight. Despite the fact that they are having problems with pressurization integrity between the Soyuz orbital and descent modules - indicating that there could be trouble with the descent module hatch - they nevertheless give the crew the okay to detach from the ISS, only to have trouble with pressure integrity after orbital module jettison and during descent.
This approach is not solely a Soviet/Russian problem; in the first hours after the Challenger accident, some at NASA started speculating that the accident was due to the self-destruct system accidentally activating rather than the fact that they launched the Shuttle in conditions outside of its operating specifications despite warnings that the launch was unsafe.
One gets the feeling that they would have much preferred that it had been a unexpected problem with the self-destruct system, as that would have left everyone off of the hook in regards to the launch decision.
Pat .
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