Soyuz anomoly still an anomoly

Nobody here seemed to comment about the update to this little tale. It
seems that the bolt retrieved on orbit worked when tested so there is still
no proof of what caused those late detachments and hence the ballistic
re-entries. Of course they have moved wiring, put in more diagnostics etc in
the newer vehicles, but its still not really known what went wrong.
I guess it proves no matter how smart humans may think they are, systems and
hardware can always throw a spanner in the works by behaving in ways
unimagined.

Brian

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Brian Gaff wrote:
Nobody here seemed to comment about the update to this little tale. It
seems that the bolt retrieved on orbit worked when tested so there is still
no proof of what caused those late detachments and hence the ballistic
re-entries.


One big "debugging" difference between this and the Shuttle is that the
Shuttle gets debugging results within a week or two after launch when it
lands again, and those are used to update the next shuttle launch a
couple months later. This allows Nasa to apply and test a patch within a
couple of months, and thus multiple tests per year until they get it
right. (foam, or those electrical connectors between ET and shuttle are
good examples of this)

Soyuz's shedule is very different in this regard. It is not only the
lower flight rate, but also the fact that a soyuz is launched before the
previous one has landed.

month -6 Soyuz 1 launches.

month 0 Soyuz 2 launches
month 0 Soyuz 1 lands

month 6 Soyuz 3 launches
month 6 Soyuz 2 lands

month 12 Soyuz 4 launches
month 12 Soyuz 3 lands

month 18 Soyuz 5 lauches
month 18 Soyuz 4 lands

Month 24 Soyuz 6 launches
Month 24 Soyuz 5 launches

A landing problem in Soyuz 1 at month 0 will generate patches that will
apply to Soyuz 3 since Soyuz 2 is already in space by the time the glith
is experienced.

The patch applied to Soyuz 3 will only be tested 12 months after Soyuz 1
landing.

So it basically takes one year after a glitch to find out if the patch
has worked or not. And if "not", then it takes another year to test the
next iteration.

they can apply patches to the flights in between, but those are done
without feedback of whether that patch works or not.


NASA is lucky is that the structure of the flights makes it possible to
make multiple evolutio of patches per year dur not only to higher flight
rate, but also the fact that they can apply a patch to the next shuttle
following a landing of the previous one and thus get much faster feedback.


I guess the russians would need to install cameras on the re-entry
module to shoot the moment the explosive bolts are activated and record
it inside the re-entry module (since cameras will be destroyed during
re-entry.)