A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Space Station
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

No straight answers from NASA on depressurization event on Soyuz descent



 
 
Thread Tools Display Modes
  #11  
Old October 25th 05, 03:56 PM
Jim Oberg
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuz descent

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.


"Terrell Miller" wrote in message
.. .
Jim Oberg wrote:
Two weeks ago -- a potentially alarming safety issue.
So far, not a single useful word of reply from anyone at NASA.


snip


These are not unreasonably questions. Any appeal
to 'go use FOIA' is not, in my view, reasonable or fair.


why? If it's reasonable to ask the questions of a federal agency, why is
it unreasonable to amke sure you get an answer?



  #12  
Old October 25th 05, 05:58 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuz descent

In article . com,
wrote:
Not saying the issue should be taken lightly, but wondering if it's
medium danger / severe annoyance level, or if it's seriously life
threatening on the ground it until it's fixed level?


Sort of in between. The suits could have kept them alive had the leak
been worse. But if anything further had gone wrong, it could have been a
bad day. The margins got uncomfortably thin.

Perhaps not "on the ground until it's fixed", but I'd say "urgent flights
only until it's at least understood".
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |
  #13  
Old October 25th 05, 06:36 PM
Pat Flannery
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuzdescent



John Doe wrote:

One message I saw here had the pressure begin to drop prior to
undocking. I would ASSUME that it began to happen when the closed the
hatches and vaccumed the vestibule, at which point they may have noticed
an imperfect seal.


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. In this case it apparently showed a loss of pressure,
but Russian mission control assumed it was a screw-up on their part, and
told them to separate from the ISS anyway.
The logic of that decision is very suspect, especially given what
happened afterwards.

This is a soyuz that stayed on station for 6 months. So any leaks would
have been noticed during this time.

IF the leak happened in the hatch between the orbital module and vacuum,
The crew could have closed the hatch between the re-entry module and the
orbital module and be safe. (but without toilet and space to move around)



This seems to be a leak in the orbital module/reentry module hatch.

One has to consider that if the leak was detected prior to undocking, it
probably was probably slow enough that they decided to proceed with
undocking. It was probably felt that delaying undocking to debug the
leak wasn't worth it based on the leak rate.



The question one should ask oneself is _why_ the hatch is leaking.
If you don't know that, then there is no guarantee that it might get
considerably worse when you fire the explosive bolts to separate the
orbital module after retrofire.

So the big question is whether they lived with the leak and made use of
orbital module until it was separated, or if they closed the hatch and
stayed in re-entry module all the time. (perhaps repressurising the
orbital module once to make use of the toilet).



As long as the two modules were joined and the hatch between the two
modules was open, the leak wouldn't be noticeable.
That's why it manifested itself again after the orbital module was
separated, and reentry began.


It was probably a very minor glitch that appears to be more serious than
it was because of the "secrecy" about it. Russians should be man enough
to release the detailed information about this glitch to end any speculation.



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.

Pat
  #14  
Old October 25th 05, 07:07 PM
Pat Flannery
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuzdescent



John Doe wrote:

Derek Lyons wrote:


Unfortunatly, the evidence would have been destroyed when the orbital
module disintegrated into atmosphere.


No, the problem is with the hatch on the top of the descent module, and
that they will have.

Pat
  #15  
Old October 25th 05, 11:23 PM
Greg D. Moore \(Strider\)
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuz descent


"John Doe" wrote in message ...
"Greg D. Moore (Strider)" wrote:
As long as NASA astronauts are expected to ride Soyuz, I expect NASA to

be
forthcoming on the risks.


Reverse the table for a minute. Do you really expect the russians be the
first to release NASA information on glitches on shuttle flights that
carried russians cosmonauts ?


Umm, that's not what I'm saying, so no reveral necessary.


Do you really think NASA would be happy
with this ?

NASA is expected to be held accountable and release the informationa
about glitches on its shuttle.


Yes, and they do.

the Russians are expected to be held accountable and release the
information about glitches on Soyuz.


Which they don't, to NASA or others. But as Jim Oberg and myself are
taxpayers, I'd expect NASA to be more demanding of the Russians and then
share what they know.


As a quasi customer/guest of Soyuz, NASA itself can ask the russians for
an explanation, but it isn't its role to make that information public.


Customer/guest? Ummm, try partner.

And yes, it is its role to make that information public.



  #16  
Old October 26th 05, 01:40 AM
Terrell Miller
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuzdescent

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
  #17  
Old October 26th 05, 01:45 AM
Terrell Miller
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuzdescent

Pat Flannery wrote:

The question one should ask oneself is _why_ the hatch is leaking.
If you don't know that, then there is no guarantee that it might get
considerably worse when you fire the explosive bolts to separate the
orbital module after retrofire.


also, knowing the 'why' ahead of time gives you an idea if the leak is a
linear trendline or not, even if separation doesn't affect things. Kinda
nice datapoint to have (see Apollo 13)...


--
Terrell Miller


"Suddenly, after nearly 30 years of scorn, Prog is cool again".
-Entertainment Weekly
  #18  
Old October 26th 05, 02:10 AM
John Doe
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event onSoyuzdescent

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.

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.


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 ?

The question one should ask oneself is _why_ the hatch is leaking.


Agreed. Luckily, the deffective hatch is back on earth and they may be
able to find out what had happened to it.

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 ?
  #19  
Old October 26th 05, 04:30 AM
dmitrik
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuz descent

Henry Spencer wrote:
In article . com,
wrote:
Not saying the issue should be taken lightly, but wondering if it's
medium danger / severe annoyance level, or if it's seriously life
threatening on the ground it until it's fixed level?


Sort of in between. The suits could have kept them alive had the leak
been worse. But if anything further had gone wrong, it could have been a
bad day. The margins got uncomfortably thin.

Perhaps not "on the ground until it's fixed", but I'd say "urgent flights
only until it's at least understood".


I guess when they first noticed a leak during pre-undocking leak-check
they considered it to be small enough. They only spent 6 extra minutes
or so trying to fix it. This is just about enough time to open the
hatch, visually check that the rubber seal looks intact and there is no
FODs, then close the hatch and re-check it again. Maybe they simply
underestimated it. It it probably difficult to measure dp/dt accurately
with all those systems working. I don't know what the standard
procedure is when the hatch is leaking but there must be something you
can do, some sort of sealant can be applied or they may have spare
rubber seals or something like that. They could have spent more time on
it but that would've mess up their landing schedule.
BTW I think they have at least 2 backups for such leaks: portable O2
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.

I guess it was fairly serious but one-off like that kinked tube during
EVA. The right solution may be to inspect the seals more often while in
orbit, schedule more time on leak checks and don't breathe loudly while
doing it. They may also look at pressure sensors.

  #20  
Old October 26th 05, 08:38 AM
John Doe
external usenet poster
 
Posts: n/a
Default No straight answers from NASA on depressurization event on Soyuzdescent

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 ?
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Unofficial Space Shuttle Launch Guide Steven S. Pietrobon Space Shuttle 0 September 2nd 05 04:13 AM
Sandia National Lab assists NASA with several shuttle projects (Forwarded) Andrew Yee Space Shuttle 0 August 21st 05 06:06 PM
JimO writings on shuttle disaster, recovery Jim Oberg Policy 0 July 11th 05 06:32 PM
Review board says shuttle safe despite NASA failure to fully implement three CAIB recommendations Jacques van Oene Space Shuttle 3 July 1st 05 09:25 PM
Unofficial Space Shuttle Launch Guide Steven S. Pietrobon Space Shuttle 0 September 12th 03 01:37 AM


All times are GMT +1. The time now is 10:16 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.