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> Contrary to popular belief, the heat a spacecraft faces on reentry isn't generated by simple friction but rather by ram pressure—the fast-moving shuttle compresses the air in front of it, forming a massive shock zone in which air molecules ionize and break apart.

Finally! It always annoys me when people, even those who should know better, call it friction.



It is almost perfect adiabatic process. Or the ionization helps to heat even further?


When gas is compressed, it heats up. Moving rapidly through the air compresses the air in front, so it heats up.

It's as simple as that.

The ionization has nothing to do with it, though that probably reduces the heat slightly as it takes energy to ionize a gas.


Ionization actually reduces the effective temperature massively - from O(v^2) to O(v) at high (read: re-entry-like) velocities.


Is friction a % of the heating, or is it negligible?




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