Near Term Mars and Lunar In Situ Propellant Production (ISPP): Complexity vs. Simplicity
AbstractÂ
This study analyzes the challenges and complexity of lunar ISPP vs. Mars ISPP and finds that lunar ISPP is so challenging it might not even be feasible, and if it is feasible, the payoff is limited while the investment is likely to be great. By contrast Mars ISPP based on atmosphere only is relatively simple with high payoff. A great foundation was laid for Mars ISPP by the MOXIE Project. The field of solid-oxide electrolysis is active and burgeoning for terrestrial applications to climate control. NASA can leverage technology advances in that field at relatively moderate investment levels to further advance Mars ISPP.
NASA is now embarked on a major initiative to return humans to the Moon whereas a human expedition to Mars is likely to be at least several decades in the future. As a result, NASA is heavily focused on lunar ISPP and seemingly has diminished interest in solid oxide electrolysis of Martian CO2 to O2 after an extremely successful demonstration on Mars by MOXIE. This might make sense at first glance, but when the two leading candidates for lunar ISPP are analyzed in detail, it is found that they are extremely difficult and challenging to implement, the effort and investment involved in developing and implementing them are high, and the potential payoff is limited. By contrast, Mars ISPP by solid-oxide electrolysis (SOEC) of CO2 is comparatively simple, reliable and has high payoff. A SOEC system is basically landed, and a switch is turned on. The only feedstock is the ubiquitous atmosphere. Lunar ISPP involves a seemingly endless number of complex dynamic steps including autonomous traverses of excavator/haulers to unearth (unmoon?) regolith and deliver it to and from a reactor.
All ISPP processes are power hungry. Power for Mars ISPP utilizes the same power system used for life support prior to human landing. Power for lunar ISPP is required in addition to power for life support.