Recent development status of Oxygen Generation System for future exploration missions

Japan Aerospace Exploration Agency (JAXA) has been developing a highly reliable air revitalization system with a smaller supply for future manned space missions. In this paper, we report the results of long-term continuous operation of the Oxygen Generation System using a sub-scale water electrolysis cell with Nafion membranes or membranes being developed by JAXA. In this study, continuous operation up to 2000 hours was achieved and the characteristics of the two types of membranes were determined. In addition, data contributing to the lifetime of the water electrolysis cell, ion exchange resin, gas-liquid separator, and the hydrogen sensors in the oxygen line were obtained. This paper also presents the lessons learned for the entire system through long-term operation.