Large-Scale Demonstration of Molten Regolith Electrolysis for Oxygen Production on A Relevant Environment

In late 2024, Kennedy Space Center (KSC), in collaboration with Lunar Resources Inc., conducted a large-scale demonstration of oxygen extraction from lunar regolith simulant using Molten Regolith Electrolysis (MRE). The experiment featured the LR-1 reactor, developed by Lunar Resources Inc., which processed 25 kg of regolith simulant and achieved an average oxygen production rate of 0.07 kg/hr under vacuum conditions. The electrochemical process was sustained for 9 hours, during which the regolith was maintained in a molten state, enabling continuous electrolysis. The reactor performed its functionalities inside the Atmospherically Sealed Simulator for In-situ System Testing (ASSIST) retrofitted to provide relevant environment conditions to the experiment while exposed to high temperatures. A custom-built Volatile and Oxygen Measurement System (VMOMS) provided real-time monitoring and characterization of gas production throughout the experiment. Post-test analysis included sampling the reduced regolith to assess compositional changes. The experiment also validated that the process of Joule-heating of molten regolith could maintain the high-temperature regime necessary for sustained electrolysis. This demonstration marks a significant step toward maturing critical in-situ resource utilization (ISRU) technologies that support long-duration human presence on the Moon. The results and findings from this test will be detailed in this paper.