Re: Soyuz TMA-11 Comes Home, More or Less...



Dr.Colon.Oscopy@xxxxxxxxx wrote:

Tonight NBC news had some locals who had seen it come down and one
said "the parachute was on fire". Discounting any possible confusion
with "thump down"this is a whole other story. Could ballastic
reentry have done this (if true)? Sort of reminds me of Komarov's
reentry...................Doc
Soyuz 5 suffered parachute heat damage when it started reentering pointy-end first after the service module failed to separate.
In Komarov's case the parachutes barely got out of the storage containers due to a foul-up during construction.
If the chute was damaged or was smoldering during landing, that would suggest either a problem with the pyrotechnic deployment system or something very abnormal during reentry that exposed the forward body of the spacecraft to reentry heating. damaging the hatches over the main and reserve chutes, such as tumbling or wobbling of some sort.
During a ballistic reentry the capsule is put into a slow roll for stability and even heating of the heat shield and exterior.
If it wasn't put into that roll, it might start wobbling on the way down.
Interesting facet of the story is that for some reason the landing was about 20 minutes later than expected:
http://www.wtte28.com/template/inews_wire/wires.international/20d664c8-www.wtte28.com.shtml
That suggests a late or not completely successful retro burn, as the ballistic reentry would get you down faster than the normal one. What's really odd is a retro burn 20 minutes late would put you _way_ off course, in fact it might put you down somewhere in the Pacific Ocean.
If there is a problem with the retro engine (they have deleted the twin nozzle back-up engine on the TM and TMA IIRC) SOP says to do a series of orbits till in the intended reentry area again, not to fire the retro late, as landing in rough territory can be fatal.... you might end up rolling down a mountain like Soyuz 18-1, or hanging in a tree with hungry wolves around the spacecraft, like Voskhod 2 (one notes that those wolves get a little larger, closer, and more hungry every time Leonov tells that story. Soon, I expect them to be described as werewolves.) ;-)
Another possibility would be a complete failure of the retro engine and a reentry burn done via the RCS engines for braking.
That would be hard to do in a way that would put you down in a predicted spot.
I think a lot of interesting things about this mission's end will come out in the next few days.

Pat
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Relevant Pages

  • Re: Soyuz TMA-11 Comes Home, More or Less...
    ... reentry have done this? ... Soyuz 5 suffered parachute heat damage when it started reentering ... That suggests a late or not completely successful retro burn, ... If there is a problem with the retro engine (they have deleted the twin ...
    (sci.space.history)
  • Re: Space Parachutes
    ... Let us assume that you have some way to do a reentry burn (handheld ... You would feel the first deceleration much higher than ordinary ... deceleration would cause the parachute to completely unfold. ... the parachute and the astronaut survives further, you would see 8 to 10 ...
    (sci.space.policy)