How Do Astronauts Survive the Heat of Reentry?
Insulating materials, like the tiles on the Space Shuttle, shield a spacecraft from the heat of reentry. A spacecraft’s shape also plays a role. Besides slowing the vehicle by creating drag, a blunt shape helps to maintain an insulating cushion of air between the spacecraft and the shock wave it creates.
Another way to protect a vehicle from reentry heating is by using an ablation shield, like those on the Mercury, Gemini, and Apollo spacecraft. These shields were covered with a material that burned off (ablated) at extremely high temperatures and dissipated the heat. Unlike the tiles on the Shuttle, ablation shields can only be used once.
Space Shuttle tiles are made of a lightweight, ceramic material. They are used on the Shuttle to insulate the vehicle from the searing heat of reentry.