Honda to test electrolysis system on International Space Station

Honda R&D Co., Ltd. has announced that it will test a high-differential pressure water electrolysis system aboard the International Space Station (ISS). This effort is being conducted in collaboration with Sierra Space and Tec-Masters. The system is part of a broader development of a regenerative fuel cell system, which Honda describes as a circulative renewable energy system designed to support energy needs in space environments, including future habitation on the Moon.

The regenerative fuel cell system is intended to produce oxygen, hydrogen, and electricity from water and sunlight, forming a closed-loop energy cycle. During the Lunar Day, the system uses solar power to perform water electrolysis, separating hydrogen and oxygen. During the Lunar Night, the stored hydrogen and oxygen are recombined in a fuel cell to produce electricity and water. The water produced is recycled back into the system. The design is intended to reduce the number of tanks required by using high-pressure gas storage and aims to minimize maintenance through the elimination of mechanical compression.

The test aboard the ISS will focus on the core component of the electrolysis system, examining its efficiency and reliability under microgravity conditions. Sierra Space will act as the space mission integrator, coordinating with NASA to deliver the system via its Dream Chaser spaceplane. Tec-Masters will serve as the ISS technology expert during the testing process.

In late 2024, Honda established a Space Development Division within American Honda. The new division is focused on enhancing collaboration with the U.S. space industry and supporting the application of Honda’s technologies to space-based activities, including long-term lunar development.