Within the next 15 years, NASA, China, and SpaceX plan to send the first crewed missions to Mars. In all three cases, these missions are meant to culminate in the creation of surface habitats that will allow for many returns and—quite possibly—permanent human settlements. This presents numerous challenges, one of the greatest of which is the need for plenty of breathable air and propellant. Both can be manufactured through electrolysis, where electromagnetic fields are applied to water (H2O) to create oxygen gas (O2) and liquid hydrogen (LH2).