Nitrogen

Nitrogen, the 7th element in the known periodic table, has many uses. In Hellion, it is primarily used as an atmospheric modifier, as fire suppression, and RCS (maneuvering) fuel. An environment of pure oxygen would be both a major flammability hazard and make those breathing it considerably high. By mixing nitrogen gas into the environment, it maintains comfortable air pressure as a "filler gas" without the liabilities. If nitrogen is sufficient as a filler gas, it is sufficient as RCS fuel during EVA. In the use as a fire suppressant, it is sufficient for both chemical and electrical fires as it displaces oxygen from the heat source.

Nitrogen is harvested in Hellion by processing nitrates, which are found in asteroids. By mining raw resources and processing through refining equipment, nitrogen can be stocked into fire extinguishers, suit packs, canisters, and the station's Life Support System.