Demonstration of Paragon’s ISRU Propellant Production Subsystem Electrolyzer and Electrolysis Assembly

To better sustain long term lunar activities, in-situ resource utilization (ISRU) has been proposed for processing the regolith-bound water-ice to provide fresh water, breathable oxygen, and rocket propellant for lunar exploration missions. However, the water-ice is found concurrently with other typically volatile species that would contaminate and degrade downstream processing systems. Paragon Space Development Corporation®, along with their partner, Giner, Inc., has been developing the ISRU-derived water purification and In-situ Hydrogen Oxygen Production (IHOP) subsystem to collect, purify, and process water-ice from permanently shadowed regions (PSRs) on the lunar surface to generate hydrogen and oxygen, incorporating state-of-the-art technologies for water-based ISRU. The primary water purification component of the IHOP subsystem concept is Paragon’s Ionomer-membrane Water Processor (IWP) technology that can selectively transport water vapor through the membrane while rejecting contaminant components. The water electrolysis is accomplished by Giner’s lightweight, proton exchange membrane (PEM) aerospace electrolyzer optimized for ISRU applications. This paper presents results, analysis, and discussion of experimental investigations to demonstrate the performance, endurance, and robustness of the electrolyzer, along with initial demonstration of the electrolysis assembly of the IHOP subsystem. The first build of the electrolyzer stack was tested for a cumulative runtime of 6,000 hours to verify long-term durability and performance. A second build was put through four freeze-thaw cycles with performance testing before and after each cycle to show robustness through non-operational environmental conditions experienced on the Moon. Further, the electrolyzer balance of plant assembly was built and tested. Results met the nominal electrolyzer subsystem performance requirements. The integrated IHOP subsystem will be demonstrated with both water purification using a simulated lunar volatile contaminant load and water electrolysis of the resulting water operating together in future testing.