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#21
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No straight answers from NASA on depressurization event on Soyuzdescent
John Doe wrote: Pat Flannery wrote: The leak was noticed prior to undocking; apparently there is a test where they enter the reentry module and seal the hatch to the orbital module, then lower the pressure in the orbital module to make sure the hatch joining the two maintains pressure integrity before they separate from the station. OK that changes things a bit. On the other hand, if the leak rate was steady, they would still have been able to decide if the loss of pressure between time of orbital module separation and time of reaching 10,000 feet altitude would have be low enough that it wasn't a concern. I can also see this as having taken some of their time after unbdocking to perhaps test, examine the hatch of the descent module. The leak would only show up once the orbital module was detached, and that occurs after retrofire and shortly before actual reentry begins, so it wouldn't be a good idea to start climbing around in the reentry capsule at that point. One of the things that may have led to mission control telling them to undock despite the possible leak could be the timeline constraint to land the capsule in the intended recovery area...delay things too long and you end up at the wrong orbital geometry to land at the planned site, and have to come up with a new timeline for reentry and landing. Do they have any data on g forces/impact force at the time that soyuz docked ? When they moved the soyuz from one port to another, would they have performed the same tests ? (which, if they were successful, would indicate that the leak problem would have been caused after/during that manoeuver. That I'm not sure of The dockings could be done with the hatch between the orbital and reentry module in the open position. You probably don't want to open and close the hatch more times than is necessary for fear of damaging its seals. told them to separate from the ISS anyway. The logic of that decision is very suspect, especially given what happened afterwards. What did happen afterwards ? That's when the leak reappeared during descent, it occurred once they had jettisoned the orbital module. What makes this spooky is how this is very close to what happened to Soyuz 11, and led to the death of its crew: http://www.astronautix.com/flights/soyuz11.htm "After the crew has left the station, taken their seats in the capsule, and closed the hatch between the Soyuz BO orbital module and SA re-entry capsule, the strained voice of Volkov comes from space: 'Hatch not hermetically sealed? What's happening? What's going on?'. All this response to the fact that the caution and warning panel 'Hatch open' light has not gone out. Yeliseyev calmly advises the crew, 'Don't panic. Open the hatch, and move the wheel to the left to open. Close the hatch, and then move the wheel to the right six turns with full force'. The crew does this several times, but the light still won't go out. On a final attempt, with 6.5 turns of the wheel, the light goes out. On the second half of he 15th orbit, the crew lowers the pressure in the BO to 160 mm, and the hatch proves to be air-tight. On the 16th orbit the crew separates their Soyuz from the Salyut station. At 21:35 they report normal separation and that they 'can see how the station moves away from the spacecraft'. They have enough propellant to stop the separation velocity, and take photographs of the station from 10 to 15 m away. They then back away to 30-40 m, and Patsayev takes another set of photographs documenting the condition of the station. * 1971 Jun 29 - Landing of Soyuz 11 Return Crew: Dobrovolsky http://www.astronautix.com/astros/dobolsky.htm, Patsayev http://www.astronautix.com/astros/patsayev.htm, Volkov http://www.astronautix.com/astros/volkov.htm, Nation: USSR. The re-entry capsule was recovered June 29, 1971 23:17 GMT, but when the hatch was opened it was found that the crew had perished due to a loss of cabin atmosphere. A pressure equalization valve was jerked loose at the jettison of the Soyuz Orbital Module. The valve was not supposed to open until an altitude of 4 km was reached. The three-man crew did not have space suits. The Soyuz was thereafter redesigned to accommodate only two crew, but in spacesuits. The actual Soyuz 11 Prime Crew was Leonov, Kubasov, and Kolodin. Dobrovolskiy, Volkov, Patsayev were their backups (and support crew to Soyuz 10). Kubasov was grounded by physicians few days before launch, and the back-up crew ended up going instead." They're probably concerned that their decision to allow to allow the Soyuz to separate from the ISS despite the leak indication would look flawed...as indeed it was. What have the astronauts actually revealed that is factual ? Any leak rates ? Was the leak generating a loud hiss ? Was it noticeable or was it just a very tiny leak that was noticed only be the precise instruments ? Ground control apparently noticed it on their instruments: http://www.msnbc.msn.com/id/9697668/ Pat |
#22
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No straight answers from NASA on depressurization event on Soyuz descent
I have the precise psi values but did not
use them because the number was on a very tightly-guarded memo and would point to a very small group of suspects. So I converted to percentages, retaining accuracy while protecting source. "John Doe" wrote in message ... dmitrik wrote: repress bottle and suit air. They did repress the cabin with O2 but I don't know whether they had to switch completely to suit air. Does anyone know what pressure the cabin went down to before they released some O2 ? I assume it starts off at 14.7 when they leave the station, right ? Also, between the time they undock from orbital module and the time the hatch is opened on the ground, wouldn't O2 have to be released from time to time even in normal circumstances to keep the 3 occupants awake in this tight space ? If the cabin is at 14.7 and the occupants close the visor of the sokhol suits, would they then be getting 100% O2 at 14.7 ? or just mixture of N2 and O2 ? If cabin were truly leaking, I take it that the suits would drop down to about 5psi, at which point it would be pure O2 into the suits ? have they released any information on whether the leak was audible or not ? If it was not audible, could it have been a faulty valve instead of actual hatch leaks ? Is it possible that this event was so trivial that the cosmonauts didn't bother doing anything out of the ordinary and thus this would explain why there is so little information about it ? |
#23
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No straight answers from NASA on depressurization event on Soyuz descent
No, it's NASA's bad, and continues to be.
"Terrell Miller" wrote in message news Jim Oberg wrote: Here's why. It is a 'news story' request that requires a degree of timeliness, while the FOIA channel is a guaranty of MONTHS of delay. It is USED to insure that kind of delay, to squelch public interest in the story. sorry Jim, I misread your original post: I thought you were saying it was unfair for a *non-NASA* entity to submit a FOIA, but what you said was that it's unfair for NASA to ask you to request the data that way instead of giving you a straight answer, to which I totally agree. My bad. -- Terrell Miller "Suddenly, after nearly 30 years of scorn, Prog is cool again". -Entertainment Weekly |
#24
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No straight answers from NASA on depressurization event on Soyuz descent
On Thu, 27 Oct 2005 10:38:27 -0500, Jim Oberg wrote
(in article ): "John Doe" wrote in message ... dmitrik wrote: repress bottle and suit air. They did repress the cabin with O2 but I don't know whether they had to switch completely to suit air. Does anyone know what pressure the cabin went down to before they released some O2 ? I assume it starts off at 14.7 when they leave the station, right ? Also, between the time they undock from orbital module and the time the hatch is opened on the ground, wouldn't O2 have to be released from time to time even in normal circumstances to keep the 3 occupants awake in this tight space ? If the cabin is at 14.7 and the occupants close the visor of the sokhol suits, would they then be getting 100% O2 at 14.7 ? or just mixture of N2 and O2 ? If cabin were truly leaking, I take it that the suits would drop down to about 5psi, at which point it would be pure O2 into the suits ? have they released any information on whether the leak was audible or not ? If it was not audible, could it have been a faulty valve instead of actual hatch leaks ? Is it possible that this event was so trivial that the cosmonauts didn't bother doing anything out of the ordinary and thus this would explain why there is so little information about it ? I have the precise psi values but did not use them because the number was on a very tightly-guarded memo and would point to a very small group of suspects. So I converted to percentages, retaining accuracy while protecting source. Um . . . by saying that just now, didn't you just essentially point out your source if anyone happens to read s.s.h or s.s.s ? -- "Fame may be fleeting but obscurity is forever." ~Anonymous "I believe as little as possible and know as much as I can." ~Todd Stuart Phillips www.angryherb.net |
#25
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No straight answers from NASA on depressurization event on Soyuzdescent
Jim Oberg wrote: I have the precise psi values but did not use them because the number was on a very tightly-guarded memo and would point to a very small group of suspects. So I converted to percentages, retaining accuracy while protecting source. Do you have any detailed info on what the pressure drop during the descent module hatch seal test before the undocking from the ISS was? Pat |
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