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Old November 5th 04, 10:13 PM
Reed Snellenberger
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"Jim Oberg" wrote in
:


Any more information about this apparent 'dent'? When was it first
'discovered'? What was the last previous time that area was surveyed
when the dent WASN'T there? Has anything like it been seen anywhere
else on the exterior? Seems like the shielding is doing its job --
what might have happened if the event had occurred in a region WITHOUT
shielding?


If you're looking into this, it'd be interesting to find out whether NASA
has any plans/capabilities to replace these panels on-orbit (I know there
is the ability to install them as an upgrade on the Russian structures)?
I'd think it would be a little useful to inspect damaged panels to
evaluate the performance of the shielding.

Secondary question: The station is oriented (generally) with the PMA/Lab
end facing in the direction of "travel". Is the shielding roughly
symmetric, or is it thicker on the "forward" and "spacewards" sides? I'm
guessing that the probability of micrometeroid and/or debris impact on
the earth-facing side is much lower than those sides, and that the
probability of damage to the "rear-facing" surfaces would be somewhere
between those two extremes.

If I remember the details of the LDEF experiment correctly, it drifted in
a gravity gradient orientation (long axis pointed towards earth) and
wouldn't have provided much useful data about the isotropy of the
micrometeroid distribution. The only spacecraft I can think of that have
been long-duration, fixed-orientation (mostly), and human-inspectable
have been ISS, Mir, Salut, and Skylab.

--
Reed