Soyuz TMA-12 faulty

Pat Flannery writes:

Jochem Huhmann wrote:

I don't think anyone can quantify the probability of the crew being
killed. There's just not enough information available.
Do you really want to find out via real-world experience?

Depends...

You can't quantify the actual lethality risk of a Soyuz reentry with the
service module still attached with three reference points on the graph,
but this is damn near as off-nominal and dangerous as it gets.
That's why I said 10% _minimum_.

I'm not totally sure what's going on on the russian side here. Either
they're a a bunch of irrational fools or they have looked at the
evidence and came to the conclusion that even with the service modul not
fully separated you can rely on it to come off in time with only very little
real danger of causing anything more harmful than a ballistic reentry.
And since they certainly have acted rather rational when it comes to
crew safety in the past and have access to data and flown hardware I
would tend to the latter.

I agree with you that this is a very unhappy situation and if I would be
the tourist scheduled to fly back with that Soyuz I would prefer to
stay home.

Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

Jochem Huhmann wrote:

I'm not totally sure what's going on on the russian side here. Either
they're a a bunch of irrational fools or they have looked at the
evidence and came to the conclusion that even with the service modul not
fully separated you can rely on it to come off in time with only very little
real danger of causing anything more harmful than a ballistic reentry.

Had it in fact caused nothing more harmful than a ballistic reentry,
you'd have a point.

And since they certainly have acted rather rational when it comes to
crew safety in the past and have access to data and flown hardware I
would tend to the latter.

By those standards, how NASA acted prior the loss of Challenger and
Columbia should have gotten numerous engineers and managers large cash
awards and promotions for meritorious service.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Jeff Findley wrote:
The Soyuz 11 did a perfect reentry and landing, but unfortunatly all the
air had leaked out, so the crew was dead when it landed.
Then there was the one that rolled down the mountainside, and the other
one that descended into the lake.
Yet another Soyuz was supposed to have landed right next to a small rural
school.


Hand waving doesn't make for good statistics. Try again.


No one really knows just what abnormal events occurred on all of their
Soyuz missions, as they were mum about flight details during the Soviet era.
James Oberg took a stab at trying to get some quantifiable data in this
regards back in 1997: http://www.jamesoberg.com/soyuz.html

Pat

(Derek Lyons) writes:

Jochem Huhmann wrote:

I'm not totally sure what's going on on the russian side here. Either
they're a a bunch of irrational fools or they have looked at the
evidence and came to the conclusion that even with the service modul not
fully separated you can rely on it to come off in time with only very little
real danger of causing anything more harmful than a ballistic reentry.

Had it in fact caused nothing more harmful than a ballistic reentry,
you'd have a point.

Well, apart from subjective accounts of one crew member and quite
sensational media reports we have nothing substantial to support the
view that there was much more than a ballistic reentry. Or have we? The
thing(s) got down to the ground in one piece after all. The service
module not separating is certainly not good, but the Soyuz is up there
and the next one will hopefully have better quality control and so: what
to do?

And since they certainly have acted rather rational when it comes to
crew safety in the past and have access to data and flown hardware I
would tend to the latter.

By those standards, how NASA acted prior the loss of Challenger and
Columbia should have gotten numerous engineers and managers large cash
awards and promotions for meritorious service.

I think you know what I mean. If there would be a real, foreseeable
danger for the crew the russians wouldn't pretend there isn't. And
spaceflight isn't totally danger-free after all. I'm quite sure that the
crew of the next Soyuz knows more than I or you or Pat and if they don't
speak up I think we should respect that.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

Jochem Huhmann wrote:
I agree with you that this is a very unhappy situation and if I would be
the tourist scheduled to fly back with that Soyuz I would prefer to
stay home.


Here's the tourist BTW: http://en.wikipedia.org/wiki/Richard_Garriott

Pat

Jochem Huhmann wrote:

(Derek Lyons) writes:

Jochem Huhmann wrote:

I'm not totally sure what's going on on the russian side here. Either
they're a a bunch of irrational fools or they have looked at the
evidence and came to the conclusion that even with the service modul not
fully separated you can rely on it to come off in time with only very little
real danger of causing anything more harmful than a ballistic reentry.

Had it in fact caused nothing more harmful than a ballistic reentry,
you'd have a point.

Well, apart from subjective accounts of one crew member and quite
sensational media reports we have nothing substantial to support the
view that there was much more than a ballistic reentry. Or have we?

We have pictures of the badly burned and damaged TMA-11 craft, along
with accounts of systems damage. (Loss of antenna.)

The thing(s) got down to the ground in one piece after all.

So did the O-Rings, 48 times. Then came the 49th and 50th...

And since they certainly have acted rather rational when it comes to
crew safety in the past and have access to data and flown hardware I
would tend to the latter.

By those standards, how NASA acted prior the loss of Challenger and
Columbia should have gotten numerous engineers and managers large cash
awards and promotions for meritorious service.

I think you know what I mean. If there would be a real, foreseeable
danger for the crew the russians wouldn't pretend there isn't.

Never mind the fact that they have a history of covering up safety
related issues eh?

And spaceflight isn't totally danger-free after all. I'm quite sure that
the crew of the next Soyuz knows more than I or you or Pat and if they don't
speak up I think we should respect that.

Ah yes, when all else fails, break out the flags and patriotic
anthems.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

"Pat Flannery" wrote in message
news:bpadndwvsNOPyKHVnZ2dnUVZ_sWdnZ2d@northdakotat elephone...

Jeff Findley wrote:
The Soyuz 11 did a perfect reentry and landing, but unfortunatly all the
air had leaked out, so the crew was dead when it landed.
Then there was the one that rolled down the mountainside, and the other
one that descended into the lake.
Yet another Soyuz was supposed to have landed right next to a small
rural school.


Hand waving doesn't make for good statistics. Try again.

No one really knows just what abnormal events occurred on all of their
Soyuz missions, as they were mum about flight details during the Soviet
era.
James Oberg took a stab at trying to get some quantifiable data in this
regards back in 1997: http://www.jamesoberg.com/soyuz.html

True, but it's very hard to point to a bunch of near misses and extrapolate
just how close the crews were to dying. That and these are the near misses
we know about. There may be serious problems with the system that simply
have not surfaced in the few flights that have been flown. And there may be
serious problems that have been presenting themselves, but no one has
recognized them as being serious.

The real problem with any safety assertion for Soyuz is caused by lack of
flight data. The flight rate of Soyuz is so low that it's extremely hard to
get a handle on just how safe, or dangerous, it really is.

Also, since it's expendable, it's per flight safety rate is far more
sensitive to production problems than a typical reusable aerospace vehicle.
The current problem with DM/SM separation appears to be just such a problem.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

Jeff Findley wrote:

Also, since it's expendable, it's per flight safety rate is far more
sensitive to production problems than a typical reusable aerospace vehicle.

At the moment, there's only one "typical reusable aerospace vehicle" to
compare it to, and that's the Shuttle, which hasn't exactly been trouble
free as far as groundings go.
So one the one hand you have two existing systems with their strengths
and shortcomings, and on the other your hypothetical reusable vehicle
that doesn't even exist as even a design yet...and your estimates of its
strengths and shortcomings.
Which is exactly how the STS program got started; it looked great on
paper - but when built it was nowhere near the wonder machine that had
been promised in regards to operating costs, turn-around time, on time
launch, or overall safety.
So you aren't just comparing apples and oranges, you are comparing a
pair of decades-old apple trees to a orange seed, and hoping for big
things around ten or twenty years from now.
Not only are the chickens not yet hatched, the eggs haven't even been
laid yet.

Pat

"Pat Flannery" wrote in message
dakotatelephone...


Jeff Findley wrote:

Also, since it's expendable, it's per flight safety rate is far more
sensitive to production problems than a typical reusable aerospace
vehicle.

At the moment, there's only one "typical reusable aerospace vehicle" to
compare it to, and that's the Shuttle, which hasn't exactly been trouble
free as far as groundings go.

I didn't mean resuable launch vehicle. To date, there has been no sane
resuable launch vehicle built. DC-X/XA was a step in the right direction,
but it was obviously a baby step. However, it did show that LOX/LH2 engines
could be reused in a sane manner (i.e. gas and go).

So one the one hand you have two existing systems with their strengths and
shortcomings, and on the other your hypothetical reusable vehicle that
doesn't even exist as even a design yet...and your estimates of its
strengths and shortcomings.

It's a given that expendables are more prone to failure than a reusable
vehicle of the same complexity. The reason being that your expendable will
always suffer from the infant mortality problem far more than the reusable.
This is due to the simple fact that you simply cannot do a full test of an
expendable. It's one and only full test is, by definition, its one and only
flight to orbit.

Outside of expendable launch vehicles and military ordinance like missiles,
there are precious few examples of expendable aerospace vehicles costing
multiple millions of dollars. There are very good reasons for this.

Which is exactly how the STS program got started; it looked great on
paper - but when built it was nowhere near the wonder machine that had
been promised in regards to operating costs, turn-around time, on time
launch, or overall safety.
So you aren't just comparing apples and oranges, you are comparing a pair
of decades-old apple trees to a orange seed, and hoping for big things
around ten or twenty years from now.
Not only are the chickens not yet hatched, the eggs haven't even been laid
yet.

I'll agree that a sane reusable launch vehicle has not yet been built;
however, that's not proof that such a vehicle isn't possible.

The closest we've come so far in an operational launch system are aircraft
used to drop expendable launch vehicles like Pegasus. Everything else
approaching sane reusability in rocket powered vehicles have been
experimental vehicles like the X-15 and the DC-X/XA.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

It's a given that expendables are more prone to failure than a reusable
vehicle of the same complexity.

Just so - the question being: can a reusable vehicle of the same
complexity actually be built, or is it implicit in the reusablity that
the complexity is higher?

Jan