[FPSPACE] confirmed -- Soyuz entry nearly ended in total disaster
geert at navtools.nl
Tue Apr 22 22:41:21 EDT 2008
This explains why the cabine looked far more scorched and blackened then
usual on the first pictures, and it also puts into context the
description of the 'fire outside', it must have been quite a rough ride.
What worries me is that it now appears to be probably the second time
around this happened: the previous landing apparently also did not fully
separate prior reentry, two similar failures in a row makes one worry
about the condition of Soyuz TMA-12 presently docked to the ISS...
Although soyuz has proven once again to be a very sturdy craft which can
survive a lot of excess heat & force, it is probably a bit of an
overstatement to call this a safe mode of descent. The average plane is
also build to survive a scenario with one or more of its engines
failing, but that doesn't mean anyone will send a plane into the air if
there is any doubt regarding its engines...
Finally there still remains the question about telemetry and tracking:
why wasn't the DM separation failure immediately picked up by mission
control (according the reports it was noted on Soyuz 5 prior to reentry,
but in those days they still had tracking vessels) and why didn't they
notice the guidance was switching to the ballistic mode. According to
some reports, recovery forces were sent East when the cabine was not
spotted in time, mentioning that there was an 'overshoot' of the landing
target, however in fact the capsule landed far west of the target site
(short of the target) as can be expected with a ballistic reentry, so
what made them expect an overshoot?
Remember the 'old days', when the Soyuz 33 mission to Salyut 6
experienced a main engine failure (requiring a de-orbit burn with the
backup system), that failure alone was enough to place doubt on the
condition of the engine system of Soyuz 32 (then still docked to Salyut
6), so they send Soyuz 34 up unmanned with improved engines and landed
Soyuz 32 unmanned. They might have argued "well, the backup system
worked okay, so no problem", but they didn't which is the safe thing to
do in my opinion. Now we are in a situation with not one, but two, craft
having apparently the same separation problem and it gets interresting
to see how this will work out for TMA 12....
jeoberg at comcast.net wrote:
> In a replay of Soyuz-5, the TMA-11 DM failed to separate fully from the Equipment Section, and began entry sideways, severely scorching the front end of the cabin.
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