Part of the life support equipment that functions either as:
- Part of a z-suit.
- With a respirator mask to allow the wearer to breathe low pressure atmospheres such as Old Mars and Ephesus III or when the atmosphere aboard a spacecraft has been compromised by smoke.
A rebreather is a breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. As a person breathes, the body consumes oxygen and makes carbon dioxide. A person with an open-circuit breathing set typically only uses about a quarter of the oxygen in the air that is breathed in. The rest is breathed out along with nitrogen and carbon dioxide. With a rebreather, the exhaled gas is not discharged as waste:
- The oxygen is recovered for re-use by the recycler.
- The carbon dioxide is expelled.
- Oxygen is added to replace what was consumed.
If the local atmosphere is thin but breathable, a compressor and filter can be used to supply oxygen.
- A rebreather is powered by the movement of the wearer's limbs.
- A rebreather and its gaskets and filters are relatively sensitive, requiring protection from dust. Users often use a scarf to provide it with some protection.