This where the crew members live and do most of their work. When in orbit, the astronauts have to function in the microgravity of space. However, the atmosphere inside the crew compartment is controlled to be as comfortable for them as possible. The air is 80% nitrogen and 20% oxygen, close to what we breathe on Earth. The cabin pressure is set at 101.36 kilopascals with 60% humidity, while the temperature is kept between 18 degrees and 27 degrees centigrade (64 and 81F). ThatÕs warm enough for the Shuttle crew to be able to work in their shirt sleeves.

The crew compartment is divided into three different levels: the flight deck, the mid-deck, and the equipment bay.