Other Transaction Agreement to advance active reactor control through a follow-on ground test of Kilopower reactor technology

LOS ALAMOS, N.M., Oct. 21, 2026 /PRNewswire/ — Space Nuclear Power Corporation (SpaceNukes) announced today that the Defense Advanced Research Projects Agency (DARPA) has awarded the company an Other Transaction Agreement (OTA) under the Fast Capacitance (Fat Cat) program. Managed by Dr. Tabitha Dodson in DARPA’s Defense Sciences Office, the Fat Cat program seeks to advance autonomous reactor operation for national security missions. The contract supports development and ground testing of advanced reactor control technologies that extend the demonstrated capability of American nuclear power.

The award extends a continuous line of nuclear power development and builds directly on SpaceNukes’ successful nuclear power demonstration heritage. In 2018, key members of the SpaceNukes team, while employed by Los Alamos National Laboratory and NASA, performed the foundational Kilopower Reactor Using Stirling Technology (KRUSTY) work — conducting the only full-power ground test of a new American space reactor in five decades. Under the current agreement, SpaceNukes and Los Alamos National Laboratory will design, build, and conduct a follow-on nuclear ground test of a Kilopower reactor incorporating active control rod operation—an advancement beyond the passively controlled architecture demonstrated in the 2018 KRUSTY test.

“This award recognizes the maturity and continuity of the team that designed, built, and tested KRUSTY in 2018,” said Patrick McClure, COO 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.”

The phased program structure includes design, procurement, and integration gates leading to the ground demonstration, producing both nuclear-tested hardware and the engineering basis for autonomous, actively-controlled reactor operation. Integration work will be conducted at SpaceNukes’ workshop in Medina, Ohio, led by Chief Engineer Marc Gibson. The work positions American industry to provide reliable nuclear power across a broader range of mission profiles, including those requiring dynamic power management and rapid response under varying operational conditions.

“There is no substitute for demonstrated technology when American national security objectives are at stake,” said Andy Phelps, CEO of SpaceNukes. “This award lets us advance the work begun in the KRUSTY program and bring another tested capability forward for the nation.”

About Space Nuclear Power Corporation (SpaceNukes)

Space Nuclear Power Corporation was founded on the belief that nuclear power is essential to our future, both on Earth and in space. The company’s goal is to enable the successful deployment of fission reactors in space. SpaceNukes brings together the core engineering and program management team behind the foundational KRUSTY demonstration in 2018. David Poston (CTO) and Patrick McClure (COO) performed this work at Los Alamos National Laboratory; Marc Gibson (Chief Engineer) led the program at NASA Glenn Research Center. The team is joined by Omar Mireles (formerly NASA Marshall Space Flight Center) and Andy Phelps (CEO). SpaceNukes holds a license from Los Alamos National Laboratory for the Kilopower technology and operates from headquarters in Los Alamos, New Mexico, and workshops in Los Alamos with additive 3D printing and in Medina, Ohio, with thermal and vacuum capabilities.

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SOURCE Space Nuclear Power Corporation