# DARPA Awards SpaceNukes Contract to Develop Autonomous Nuclear Reactor > DARPA has awarded SpaceNukes a contract under the Fat Cat program to develop and ground-test an autonomous nuclear reactor with Los Alamos National Laboratory. - Canonical URL: https://coreiten.com/en/article/spacenukes-autonomous-nuclear-reactor-wins-darpa-contract - Language: en - Section: Energy Sources - Author: Sami - Published: 2026-10-23T04:01:33+03:00 - Modified: 2026-10-23T04:01:33+03:00 - Publisher: CoreITen (https://coreiten.com) - Keywords: SpaceNukes, DARPA, Fat Cat, KRUSTY, Kilopower, Los Alamos National Laboratory, NASA ## Summary DARPA awarded SpaceNukes a contract under the Fat Cat program to develop and ground-test an advanced autonomous nuclear reactor for national security. - SpaceNukes will partner with Los Alamos National Laboratory to design and run a ground test of a new Kilopower reactor. - Unlike the passively controlled 2018 KRUSTY experiment, this new iteration will feature active control rod operation. - The 2018 KRUSTY experiment marked the only full-power ground demonstration of a new US space reactor in 50 years. - Chief Engineer Marc Gibson will lead the integration phase at the SpaceNukes workshop located in Medina, Ohio. **Why it matters:** This initiative aims to evolve basic small reactor technology into actively regulated, autonomous power systems capable of supporting future lunar bases and defense missions. --- The Defense Advanced Research Projects Agency (DARPA) has awarded Space Nuclear Power Corporation (SpaceNukes) an Other Transaction Agreement (OTA) to develop and ground-test an autonomous nuclear reactor. As reported by Prabhat at Interesting Engineering, the contract falls under DARPA's Fast Capacitance (Fat Cat) program, which aims to advance autonomous reactor operation for United States national security missions. According to a press release cited by Interesting Engineering, the agreement funds the development and ground testing of advanced reactor control technologies designed to expand demonstrated American nuclear power capabilities. ### Building on the 2018 KRUSTY Heritage Under the new agreement, SpaceNukes and Los Alamos National Laboratory will design, construct, and run a follow-on nuclear ground test of a Kilopower reactor. This new iteration will feature active control rod operation, moving beyond the passively controlled design tested in 2018. In 2018, key members of the SpaceNukes team - then working at Los Alamos National Laboratory and NASA - conducted the foundational Kilopower Reactor Using Stirling Technology (KRUSTY) experiment. That test marked the only full-power ground demonstration of a new US space reactor in 50 years. “This award recognizes the maturity and continuity of the team that designed, built, and tested KRUSTY in 2018,” said Patrick McClure, Chief Operating Officer of SpaceNukes. “We are proud to work alongside Dr. Dodson and Los Alamos National Laboratory to deliver the next demonstrated step in American nuclear power.” ### Path to Autonomous Control and Testing The program follows a phased structure covering design, procurement, and integration checkpoints ahead of the ground demonstration. It aims to deliver both nuclear-tested hardware and the engineering foundation needed for actively controlled, autonomous reactor operation. Next steps include finalizing the design, integrating components, and running ground tests to evaluate the controller's performance. Chief Engineer Marc Gibson will lead the integration phase at SpaceNukes' workshop in Medina, Ohio. According to the company's press statement, the project positions US industry to supply dependable nuclear power across wider mission profiles, including scenarios that demand rapid response and dynamic power management under changing operational conditions. > “There is no substitute for demonstrated technology when American national security objectives are at stake. This award lets us advance the work begun in the KRUSTY program and bring another tested capability forward for the nation.” > > Andy Phelps, CEO, SpaceNukes ### Potential Applications and Current Limits Interesting Engineering notes that the project is significant because it seeks to move past demonstrating a basic small nuclear reactor toward a system that can actively regulate its own operation. In space exploration, the technology could potentially supply electricity for future lunar bases, scientific instruments, and long-duration missions, especially where sunlight is scarce and solar panels alone may not offer reliable energy. Similar systems could also potentially power remote facilities and specific defense applications requiring steady electricity. However, Prabhat notes that these remain potential use cases for the technology rather than confirmation that this specific reactor is ready for operational deployment. ## Sources - [interestingengineering.com](https://interestingengineering.com/energy/us-defense-backs-autonomously-controlled-nuclear-reactors) ## Related topics - [NASA](https://coreiten.com/en/topic/nasa)