Sierra Space has announced a collaboration with Honda and Tec-Masters to support the testing of Honda’s high-differential pressure water electrolysis system aboard the International Space Station (ISS). The project is designed to verify the efficiency and reliability of Honda’s system in microgravity as part of a broader initiative to develop regenerative fuel cell technology for sustainable energy generation in space and on Earth.
The electrolysis system is a core component of Honda’s circulative renewable energy system—an integrated platform for producing oxygen, hydrogen, and electricity. The system is intended to support sustained human habitation on the Moon by using solar energy during lunar daylight to generate hydrogen and oxygen from water. During the lunar night, the stored hydrogen and oxygen are used in a fuel cell to produce electricity, with water as the only byproduct. That water is then recycled to complete the loop.
Honda’s system was engineered for high performance, lightweight design, and reduced maintenance demands—key factors for long-term missions. Unlike mechanical compression systems, the high-differential pressure design enables high-pressure gas storage in compact containers, minimizing resupply needs. Testing aboard the ISS will allow Honda to validate its performance under the unique conditions of microgravity.
Sierra Space will serve as mission manager, coordinating with NASA and the Center for the Advancement of Science in Space (CASIS) to transport test materials aboard the company’s Dream Chaser® spaceplane. Tec-Masters will provide payload integration and certification expertise. The collaboration marks a milestone in commercial space cooperation, enabling cross-sector innovation in energy and sustainability.
“The future of innovation in space is not only commercialization, but teaming arrangements between like-minded companies to advance technology we never thought imaginable in previous decades,” said Ken Shields, Senior Director of Business Development at Sierra Space. “As we prepare for our first Dream Chaser mission to the International Space Station, this new collaboration with Honda and Tec-Masters is an additional proof point to the varied applications of our spaceplane to provide commercial transport to the space station and beyond.”
Sierra Space’s Dream Chaser spaceplane is currently undergoing final testing at NASA’s Kennedy Space Center in preparation for its first mission under NASA’s Commercial Resupply Service 2 (CRS-2) contract. The vehicle offers more than 6 metric tons of cargo capacity and is capable of returning critical payloads to Earth with less than 1.5g reentry loads via commercial runways.
Honda’s system testing is also supported by its newly established Space Development Division in the U.S., created to promote collaboration with the American space industry and expand the application of Honda’s core technologies to lunar infrastructure.
About Sierra Space
Sierra Space is a commercial space company focused on enabling new platforms in low Earth orbit and beyond. The company’s Dream Chaser® spaceplane and LIFE™ habitat modules are designed for scalable orbital infrastructure to support research, commerce, and defense. With more than 500 missions of spaceflight heritage, Sierra Space provides end-to-end services across space transport, habitation, power, life support, and subsystem integration.
About Honda
Honda R&D Co., Ltd. is leveraging its decades of hydrogen fuel cell development to support regenerative energy systems for lunar exploration and terrestrial sustainability. Honda’s circulative renewable energy platform is designed to produce and reuse oxygen, hydrogen, and electricity in closed-loop cycles. In 2024, Honda established its U.S.-based Space Development Division to support technical collaboration with the U.S. space industry and expand advanced energy solutions to support long-term habitation on the Moon.
About Tec-Masters
Tec-Masters is headquartered in Huntsville, Alabama, with additional offices throughout the United States. The company provides scientific and technological solutions for U.S. Department of Defense (DoD), NASA, and commercial programs. Tec-Masters supports federal and industry initiatives through systems integration, software development, engineering, and training services. Its work spans multiple mission areas, including spaceflight operations, payload integration, and technology development.
For more information, visit www.sierraspace.com or honda.us/SpaceDevelopment.
Sources/Photo Credits: Honda, Sierra Space
(Editor’s Note: All trademarks mentioned in this article, including company names, product names, and logos, are the property of their respective owners. Use of these trademarks is for informational purposes only and does not imply any endorsement.)
