Conceptual Design and Viability Analysis of a Lunar ROXY Pilot Plant

The reality of a future of human presence on the Moon depends on the accessibility to crucial life-support systems and elements. The most vital of all being the one element every living creature on Earth cannot live without: Oxygen. The demand for oxygen on the Moon can be met by either routinely delivering tanks from Earth or alternatively, producing it directly where it is needed using ISRU technologies. Lunar regolith consists of metal oxides and glasses and contains 45m% (mass percent) oxygen on average. ROXY (Regolith to oxygen conversion), invented and developed at Airbus, is one promising molten salt solid oxide membrane electrolysis process, capable of reducing all regolith constituents at one temperature and producing 100% pure oxygen in the meantime. The commercial demand for oxygen on the Moon is expected to grow exponentially in the coming years, not only for life support but propellant production as well. A demand of tens to hundreds of tons oxygen per year in the early 2030s is currently estimated. In order to achieve this level of production, intermediate development steps are necessary. This paper considers a concept and viability analysis of a Pilot ROXY facility, producing a minimum of 500 kg of oxygen per year as a crucial step towards the implementation of operational facilities. The oxygen production should be maximized while minimising the transportation cost of the facility itself, as well as the mass of consumables and total facility power. A design concept of the pilot plant is presented along with quantitative performance figures, expressed as figures of merit which characterize its viability.