
ISS Solar Panel Punctured by Small Stone - davidcuddeback
https://twitter.com/Cmdr_Hadfield/status/328920180241596417
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rtpg
How dangerous are small flying rocks? I mean does it really pose a big threat
to the station and the crew? His tweet seems to imply so.

I also don't know what kind of contingency plans you can have in the ISS,but
I'm not aware of how space-structural integrity works

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davidcuddeback
My intuition has always been that a stone striking a satellite is
statistically unlikely because of the vastness of space. The theoretical
possibility was always there to create immense damage (or completely destroy
smaller satellites) because of the kinetic energy involved, but so unlikely to
be near-zero.

That's what caught my eye about this tweet. It's the first time I've heard of
an actual collision between a satellite and a small stone.

As far as your question regarding the ISS, I can only imagine what would
happen if it had struck the hull. A satellite in LEO travels at around 7-8
km/s ( _kilo_ meters per _second_ ). I'm not sure what that means for the
relative velocity between the satellite and a stone---probably slower, but by
how much? Using the orbital velocity as an estimate of the relative velocity,
that's about an order of magnitude faster than most firearms, so I find it
improbable that the hull is armoured against such a strike.

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leishulang
if we have the camera precision to catch a small rock miles away, laser
interception might be doable.

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wrs
NASA says: The ISS is the most heavily shielded spacecraft ever flown.
Shielding is designed to protect critical components such as habitable
compartments and high-pressure tanks from the nominal threat of an aluminum
sphere approximately 1 cm in diameter. The ISS also has the capability of
maneuvering to avoid tracked objects.

[http://www.nasa.gov/centers/wstf/laboratories/hypervelocity/...](http://www.nasa.gov/centers/wstf/laboratories/hypervelocity/mmod.html)

