As part of a push that combines the rich history of nuclear engineering with the needs of space exploration, NASA and the U.S. Department of Energy have announced their plan to place a nuclear fission reactor on the surface of the Moon by 2030. This is part of the agency’s efforts to power its Artemis mission with a reliable energy source that would be needed for missions to Mars.
The lunar reactor design will rely on past successes such as the Kilopower project and SNAP-10A, which showed that a small fission reactor could be safe and efficient in space. In contrast to chemical and solar power, fission surface power provides the advantage of being able to supply electricity for years at a time without the need for resupply, which would be very useful for human exploration missions. The design will have to be compact enough for a heavy-class lunar lander and have the capability of producing at least 100 kW of power.
According to NASA Administrator Jared Isaacman, the project was necessary for the development of the “infrastructure to stay” on the Moon. Secretary of Energy Chris Wright termed the project “one of the greatest technical achievements in the history of nuclear energy and space exploration.” The memorandum of understanding between the agencies not only included the deployment of the reactors on the Moon but also in orbit.
The presence of competition is increasing the sense of urgency. China and Russia have already come up with a joint plan for building their own lunar reactor in the mid-2030s. This has forced U.S. officials to hasten their timelines. Former NASA Administrator Sean Duffy said that when a country establishes a lunar reactor first, it may establish a ‘keep-out’ zone and restrict entry for other countries in resource-rich areas such as water ice.
Reactor design for the Moon is an entirely different task because, in lower gravity, the behavior of liquid coolants changes, and thus different systems for liquid circulation are needed. The large differences in temperatures between day and night on the Moon require insulation and thermal management unlike anywhere on Earth. The materials used must be able to resist the effects of a vacuum and radiation, and the reactor itself must be able to function without human involvement for a decade, which nuclear specialist Katy Huff believes could be achieved using TRISO fuel and helium coolant.
The reactor will be assembled entirely on Earth with control rods inserted to prevent activation upon rocket launch. After the reactor is installed on the Moon’s surface, the process of activating the reactor will begin with the withdrawal of control rods to start the process of fission. Safety procedures, which have been refined over the years with various nuclear missions in space, will be used to ensure the least danger is caused when the reactor is launched and installed on the Moon’s surface. Highly pure fuel is not a source of radiation danger until it is used.
Although the 2030 goal is very ambitious, the agencies are utilizing their partnerships with industry leaders such as Lockheed Martin, Westinghouse, and X-energy to optimize the design and specifications. The change of the program to the NASA Exploration Systems Development Mission Directorate is expected to simplify decision-making and direct efforts toward milestone-driven deliveries. If successful, the lunar reactor will be used to power habitats and rovers on the Moon and represent a major milestone on the way to a human presence on Mars.
“For NASA and the DOE, this project is far more than simply a technical achievement—it is a declaration of the intention to be a leader in the coming age of space exploration. By combining the best of nuclear solutions with the latest advances in engineering, the United States is poised to stake its claim on the Moon that will help to determine the course of human endeavors throughout the solar system.”
