CO2 is abundant in the Martian atmosphere and can be converted in-situ into oxygen (O2) and carbon monoxide (CO). Both CO and O2 can be used in a propellant mixture, while O2 can be collected and made available for breathing. The only concrete proposal for O2 production on Mars to date is the MOXIE experiment. We propose a new and complementary approach, linking two emerging technologies: non-thermal plasmas and ion-conducting membranes. Non-thermal plasmas are highly reactive gas media sustained by electrical discharges, that offer unique ways to break the strong C=O bond by taking advantage of the energy stored in the internal degrees of freedom. The plasma will be created on top of a solid oxide membrane, with the possibility of replacing the cathode of the cell by the plasma. This will increase the flow of O2 through the membrane, since the production of O atoms in a plasma is much larger than on the surface of a normal cathode. Preliminary results [1-3] show that the Martian conditions are very favourable to ignite a plasma system and to efficiently decompose CO2. It is estimated that O2 may be produced at a rate of 14 g/h using a 6 kg plasma reactor with dimensions 25x20x5 cm, amounting to 2.3 g of O2 produced per hour per kg of equipment sent to Mars. This number is about 7.5 times higher than achieved in MOXIE, of 0.3 g of O2 per hour per kg (device of 17 kg, 24×24×31 cm, that produced 5.5g of O2 per hour). By exploring the synergistic effect of plasmas and ion-conducting membranes, we aim at defining a roadmap to mature the technology within the ESA Exploration programme and at delivering a proof-of-concept prototype to decompose CO2 directly from the Martian atmosphere. The knowledge acquired to develop ISRU for production of propellants and life support commodities on Mars will also make life on Earth more productive, clean and sustainable. It will contribute to improve CO2 utilization technologies on Earth, fostering the transition to renewable energy.
