14/03/2014 · The majority of the heat developed during reentry of a spacevehicle comes from air compression not friction. Remember, to go into space, you don't have to go very high, but to orbit you will have to go very very fast, and it's not the fall that produces the heat, it's the slowing down part.. If you had a human fall without a chute, the terminal velocity (where air resistance cancels gravity ...