Propellant storage
Propellant storage facilities are required to store propellant for return vehicles and for Mars transit vehicles. Large scale propellant storage can also serve as backup energy storage for a settlement in case of emergencies.
Contents
Oxygen storage
Cryogenic oxygen storage
Methane storage
Methane storage on Mars can use the technologies developed for natural gas (which is mostly methane) storage on Earth.
Cryogenic methane storage
Liquefied methane is cooled down to liquid form for ease and safety of non-pressurized storage. It takes up about 1/600th the volume of methane in the gaseous state (at standard conditions for temperature and pressure). It is odorless, colorless, non-toxic and non-corrosive. Hazards include flammability after vaporization into a gaseous state, freezing and asphyxia. The liquefaction process involves removal of certain components, such as dust, acid gases, helium, water, and heavy hydrocarbons, which could cause difficulty downstream. The natural gas is condensed into a liquid at close to atmospheric pressure by cooling it to approximately −162 °C (−260 °F); maximum pressure is set at around 25 kPa (4 psi). See Liquified Natural Gas.
