NASA plans to extend the three nuclear fission reactor design contracts to produce energy on the Moon to a second phase in which ONE model will be chosen ready to launch around 2030. The agency is concluding the initial phase of its Fission Energy Project on the surface, which focused on developing conceptual designs for a small electricity-generating nuclear fission reactor that could be used during a future demonstration on the Moon and to inform future designs for Mars. NASA awarded three $5 million contracts in 2022, assigning each commercial partner – Lockheed Martin, Westinghouse and IX of Houston – to develop an initial design that included the reactor; its energy conversion, heat rejection and energy management and distribution systems; estimated costs; and a development timeline that could pave the way to driving a sustained human presence on the lunar surface for at least 10 years. The agency designed the requirements for this initial reactor to be open and flexible to maintain the ability of commercial partners to contribute creative approaches to technical review. However, NASA specified that the reactor should remain below six metric tons and be capable of producing 40 kilowatts (kW) of electrical power, ensuring enough power for demonstration purposes and additional power available to operate lunar habitats, space vehicles, backup networks or scientific experiments. In the United States, 40 kW can, on average, provide electricity to 33 homes. NASA also set a goal for the reactor to be able to operate for a decade without human intervention, which is key to its success. Safety, especially with regard to radiation dose and shielding, is another key factor for the design. Beyond the stated requirements, the partners envisioned how the reactor would be powered and controlled remotely. They identified potential failures and considered different fuel types and configurations. Having terrestrial nuclear companies combined with companies with space experience generated a wide range of ideas. “We are receiving a lot of information from all three partners,” explains Lindsay Kaldon, Fission Surface Power project manager at the Glenn Research Center, in a statement. “We will have to take some time to process everything and see what makes sense to move to Phase 2 and make the best of Phase 1 to establish requirements to design a lower risk system in the future.” Open bidding for Phase 2 is planned for 2025. After Phase 2, the expected date for delivering a reactor to the launch pad is the early 2030s. On the Moon, the reactor will complete a year-long demonstration followed by nine years of operation. If all goes well, the reactor design could be updated for potential use on Mars. CONVERTERS Beyond preparing for Phase 2, NASA recently awarded contracts to Rolls Royce North American Technologies, Brayton Energy and General Electric to develop Brayton power converters. The thermal energy produced during nuclear fission must be converted into electricity before use. Brayton converters solve this by using heat differences to spin turbines inside the converters. However, current Brayton converters waste a lot of heat, so NASA has challenged companies to make these motors more efficient. While solar power systems have limitations on the Moon, a nuclear reactor could be placed in permanently shaded areas (where water ice may be present) or generate power continuously during lunar nights, which last 14 and a half Earth days.