A manned spacecraft must have a source of oxygen for the crew to breathe and a means of removing carbon dioxide, which the crew exhales. Manned space vehicles use a mixture of oxygen and nitrogen similar to the earth's atmosphere at sea level. Fans circulate air through the cabin and over containers filled with pellets of a chemical called lithium hydroxide. These pellets absorb carbon dioxide from the air. Carbon dioxide can also be combined with other chemicals for disposal.
Charcoal filters help control odors.
Eating and drinking. The food on a spacecraft must be nutritious, easy to prepare, and convenient to store. To eat, the astronauts simply mixed water into the food. Packaging consisted of plastic tubes. The astronauts used straws to add the water.