LOS ALAMOS, N.M. — The Space Nuclear Power Corporation, known commercially as SpaceNukes, announced today that it has been awarded an Other Transaction Agreement (OTA) by the Defense Advanced Research Projects Agency (DARPA). The contract is part of the agency’s Fast Capacitance, or "Fat Cat," program, which is managed by Dr. Tabitha Dodson within DARPA’s Defense Sciences Office.
The Fat Cat program is designed to drive the advancement of autonomous reactor operation for critical national security missions. Under the terms of the new agreement, SpaceNukes will spearhead the development and rigorous ground testing of advanced reactor control technologies. This initiative is aimed at significantly expanding the demonstrated operational capabilities of American nuclear power systems, laying essential groundwork for future deployments where reliability, autonomy, and rapid response times are paramount.
This latest award represents a continuation of a distinguished lineage of American nuclear power development, building directly on SpaceNukes’ successful history of nuclear demonstration projects. In 2018, key members of the SpaceNukes core team—while working in their previous capacities at the Los Alamos National Laboratory and the National Aeronautics and Space Administration (NASA)—achieved a major milestone by executing the Kilopower Reactor Using Stirling Technology (KRUSTY) project. That historic undertaking produced the only successful full-power ground test of a new American space nuclear reactor in five decades, proving the viability of small, lightweight fission power systems for use in challenging environments.
Under the current agreement, SpaceNukes will collaborate once again with the Los Alamos National Laboratory. Together, the organizations will design, build, and execute a comprehensive follow-on nuclear ground test of a Kilopower reactor. Crucially, this new iteration will incorporate active control rod operation, marking a major technological advancement beyond the passively controlled architecture that was successfully demonstrated during the 2018 KRUSTY test. While passive control systems rely on natural physical properties to regulate temperature and power output without human or mechanical intervention, active control mechanisms permit dynamic adjustments, offering enhanced operational flexibility and precise power management.
"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."
The phased structure of the program is organized around a series of rigorous design, procurement, and integration gates that ultimately culminate in the physical ground demonstration. This structured approach is expected to yield both tangible, nuclear-tested hardware and a robust engineering basis for autonomous, actively controlled reactor operation.
Execution of the integration work will take place at SpaceNukes’ specialized workshop located in Medina, Ohio, under the leadership of Chief Engineer Marc Gibson. The strategic positioning of this work is intended to position American industry to provide reliable, highly resilient nuclear power across a significantly broader range of mission profiles. These expanded profiles include operational scenarios that demand dynamic power management, continuous adaptability, and rapid response capabilities under rapidly varying environmental and operational conditions.
"There is no substitute for demonstrated technology when American national security objectives are at stake," said Andy Phelps, Chief Executive Officer of SpaceNukes. "This award lets us advance the work begun in the KRUSTY program and bring another tested capability forward for the nation."
Space Nuclear Power Corporation was founded on the foundational belief that advanced nuclear power is essential to the future of humanity, both on Earth and in the expanse of space. The company’s overarching corporate goal is to enable the successful, routine deployment of fission reactors in space to support prolonged exploration, habitation, and defense infrastructure.
The company brings together the core engineering and program management personnel who were responsible for the foundational KRUSTY demonstration in 2018. Chief Technology Officer David Poston and Chief Operating Officer Patrick McClure executed that landmark work at the Los Alamos National Laboratory, while Chief Engineer Marc Gibson led the parallel program efforts at the NASA Glenn Research Center. The leadership team also includes Omar Mireles, formerly of the NASA Marshall Space Flight Center, alongside Chief Executive Officer Andy Phelps.
Holding an exclusive license from the Los Alamos National Laboratory for the underlying Kilopower technology, SpaceNukes operates primarily from its headquarters in Los Alamos, New Mexico. The company also maintains specialized workshops in Los Alamos equipped for additive three-dimensional printing capabilities, as well as the Medina, Ohio facility outfitted with advanced thermal and vacuum testing capabilities.
