NASA and the U.S. Department of Energy signed “Accelerating American Leadership in Space Nuclear Power and Propulsion,” a 10-year memorandum effective November 1, 2026. It replaces a radioisotope power-systems agreement signed October 31, 2016, and a space-fission-systems agreement signed December 22, 2025. The framework covers nuclear-system development, research, fuel production, testing, launch integration, and operations. NASA and DOE are targeting a lunar surface reactor launch by 2030, with SR-1 Freedom intended as a milestone toward Lunar Reactor-1.[1]
The agreement assigns NASA mission authority, installation and testing, and operational data collection; DOE is responsible for design, fabrication, evaluation, testing, delivery, fuel production, nuclear-material authorization, and prelaunch technical support. For a lunar ark, fission power can reduce dependence on solar illumination, enable continuous thermal control and computing, and support resource extraction, manufacturing, communications, and biological preservation. It also creates safety, launch, fuel-supply, shielding, waste-management, and single-point-failure risks that must be treated as civilisational infrastructure concerns.[1]
The Ark team should track SR-1 Freedom and Lunar Reactor-1 milestones against the 2030 target; obtain reactor power, mass, operating life, redundancy, fuel, shielding, maintenance, and end-of-life specifications; and design preservation systems around multiple independent power sources. Research should prioritise reactor-compatible habitat architectures, buried or bermed installations, autonomous fault isolation, spare-control inventories, radiation-tolerant electronics, and procedures for safely restarting civilisation-support systems after prolonged crew absence.[1]