locarno24 said:
** e.g. a 1/4 cm micrometeorite or a bullet
Just out of curiosity, I worked out the kinetic energy of a meteorite of that size, to find what sorts of bullets would be most similar to it. I assumed a sphere of ice at the orbital velocity of the International Space Station, looked things up on Wikipedia, and did a little arithmetic:
Showing my work:
Ice density = 0.9167 g/cc
Sphere volume = 4/3 pi r^3
0.25 cm sphere volume = 4/3 pi (0.25)^3 ≈ 0.00818 cc
0.25 cm ice mass ≈ 0.00750 g
International Space Station orbital velocity ≈ 7.66 km/s
Kinetic energy = 1/2 m v^2
Kinetic energy of 0.25 cm ice sphere at 7660 m/s ≈ 220 kg m^2/s^2 ≈ 220 J
That's on a par with the .22 LR bullets listed in the Wikipedia infobox, which range from 141 J to 259 J.
In terms of damage it would do, I couldn't find information about whether an extremely small, extremely fast impact (such as ice at orbital velocity) would do more or less damage to a space suit than a small-caliber bullet of similar kinetic energy. Space suits are specifically designed to resist small, fast impacts, since that's a constant hazard in space. But does that leave them vulnerable to bullets? Or are they even more resistant to bullets? I couldn't find an answer -- probably because withstanding bullets has never been a design goal for real-world space suits.