#reentry

How Spacecraft Survive the Violence of Atmospheric Reentry

When a spacecraft plunges back into Earth's atmosphere, friction compresses the air in front of it so violently that the gas heats to thousands of degrees — hot enough to vaporize metal. Surviving this requires one of the cleverest engineering compromises in spaceflight: a shield that deliberately ablates, burning away to carry the heat with it. Without it, every astronaut return would be fatal.