5 ms·
Ah, this was the piece I was missing. I assumed the heat of impact and/or re-entry would sterilize just about anything that wasn't an engineered heat shield.
by stackghost 3mo ago
Ah, this was the piece I was missing. I assumed the heat of impact and/or re-entry would sterilize just about anything that wasn't an engineered heat shield.
- pfdietz 3mo agoThe concern in the impact is how much heat is produced in the material itself, by the shock wave. A shock wave is dissipative, producing entropy and heat as it propagates, but near the spalled surface it cancels itself out and the heating becomes small.
- pfdietz 3mo agoYou might also be interested in the story of Lew Allen's Balls (which is much less prurient than the name might suggest). These were pumpkin-sized steel spheres, coated in a thin layer of graphite, that were suspended as close as 10 meters from one of the Teapot nuclear explosions (22 kT) in Nevada. The explosion vaporized about 1 mm of graphite but otherwise didn't damage the spheres much at all. https://www.youtube.com/watch?v=by1xpy8ob8E https://www.youtube.com/watch?v=by1xpy8ob8E (starting around 5:50).