A re-entry-vehicle’s surface is coated with a material having a very high latent heat of fusion, such as carbon or ceramics. As this material evaporates or vaporizes, it soaks up large amounts of heat energy and protects the vehicle. This process is known as ablation. Ablation was used on all U.S. manned vehicles until the Shuttle. The Russians still rely on this technique and we’re going back to it.