An escape crew capsule is like a special room that is made for astronauts to use when they need to quickly get away from their spacecraft in an emergency. Kind of like a really fancy escape pod!
It has walls and a ceiling made out of strong and durable materials that can protect the astronauts from things like fire or explosions. The capsule is usually located on the top of the spaceship, so that it can quickly separate from the rest of the craft if something goes wrong.
Inside the escape crew capsule, there are comfy seats for the astronauts to sit in, and it has special equipment and supplies that they might need while they wait to be rescued. The capsule also has its own life support system, which is like a mini air-conditioning and oxygen supply unit, to keep the astronauts safe and comfortable until they can be rescued.
In case the capsule has to be used, the astronauts have to quickly buckle themselves up in their seats and hold on tight, as the capsule blasts away from the spacecraft. They will then parachute down to Earth or land in the ocean, where rescue teams will be ready to help them.