Scale Up and Coupling of the MOXIE Solid Oxide Electrolyzer for Propellant Production on Mars


The successful operation of MOXIE on Perseverance mission Sol 60 (20 April 2021) has made Mars ISRU a reality. Since delivering the Solid OXide Electrolysis (SOXE) stacks for the Mars 2020 MOXIE project in 2017, the OxEon team, with the support of a NASA NextSTEP-2 ISRU award, has designed and fabricating SOXE stacks scaled 33 times the 0.5% scale of the device in MOXIE. A system containing six such SOXE stacks will have the oxygen production capacity to supply the propellant oxidant for a human mission Mars Ascent Vehicle (MAV). The full area SOXE design produced and tested in 2018 for commercial terrestrial energy storage applications has been joined in 2021 by an ISRU variant modified for oxygen collection.

While MOXIE has proven the case for atmospheric ISRU for oxygen production, use of the cathode byproduct CO was not demonstrated. OxEon has now demonstrated production of methane using solid oxide co-electrolysis of a CO2-steam mixture to produce syngas, a mixture of CO and H2 coupled with a subsequent methanation reactor converting the syngas to methane. Methanation of synthesis gas is related to the Sabatier reaction but has the advantage of producing half the water (due to starting with CO rather than CO2) which improves the thermodynamic equilibrium extent of reaction. Near quantitative conversion of syngas to methane has been demonstrated with the OxEon integrated breadboard system. This compact system has been operated in the same JPL Mars chamber used in MOXIE development. Extraction of Mars near-surface water, combined with the OxEon integrated SOXE co-electrolysis and methanation system will enable ISRU O2-CH4 propellant production on Mars.

The program objectives and results from full-scale area stacks operating in co-electrolysis mode coupled to a methanation reactor will be discussed.


Joseph Hartvigsen, OxEon Energy, LLC, US
S. Elango Elangovan, OxEon Energy, LLC, US
Jessica Elwell, OxEon Energy, LLC, US
Michele Hollist, OxEon Energy, LLC, US
Dennis Larsen, OxEon Energy, LLC, US
Tyler Hafen, OxEon Energy, LLC, US
Don Claus, OxEon Energy, LLC, US
Skyler Valdez, OxEon Energy, LLC, US
Abel Gomez, OxEon Energy, LLC, US
Piotr Czernichowski, OxEon Energy, LLC, US
Ainsley Yarosh, OxEon Energy, LLC, US
Jenna Pike, OxEon Energy, LLC, US
Nathan Davis, OxEon Energy, LLC, US
ICES308: Advanced Technologies for In-Situ Resource Utilization
The 51st International Conference on Environmental Systems was held in Saint Paul, Minnesota, US, on 10 July 2022 through 14 July 2022.


ISRU, Solid Oxide Electrolysis, Propellant Production, Oxygen