A skydiver is doing a jump from space (high altitude balloon.) There were a number of comments on the news article asking how he wasn't going to burn up in the atmosphere. He is actually higher than several early space missions, which did require heat shields, so my challenge is this: explain why Mercury Missions needed a heat shield, but the skydiver doesn't. I'll explain how it works fully in a day or so if no one can figure it out. No googling! It's actually pretty common sense, so you should be able to figure it out without having to google. If you do google out of curiosity, just admit defeat here and don't ruin the challenge for anyone else. If you know, post it and the games over. I'm curious to see how the well science is taught in school, probably learned this in fifth grade, or should have.