U.S. Space Force Awards $161 Million to California Startup for Orbital Nuclear Reactor
The U.S. Air Force's space acquisition office has granted Antares a $161 million Strategic Breakthrough contract to develop a nuclear reactor for powering spacecraft, marking a significant step in orbital energy technology.
The U.S. Air Force's Office of the Assistant Secretary for Space Acquisition and Integration has awarded a $161 million Strategic Breakthrough contract to Antares, a California-based nuclear startup, to advance a reactor design intended to power spacecraft. The award, announced this week, represents the largest Department of War funding to date focused specifically on space nuclear power, according to the company.
The contract aims to accelerate the development of a compact nuclear reactor capable of providing reliable, long-duration power for orbital operations. Unlike solar panels, which are limited by distance from the sun and shadow periods, nuclear reactors can supply consistent energy for deep-space missions, high-power sensors, and propulsion systems. Antares will use the funds to refine its reactor design, conduct testing, and move toward a flight-ready prototype.
This award underscores a growing push by the U.S. military to secure energy independence in space. As satellites become more sophisticated and missions extend farther from Earth, the need for robust, sustained power sources has become a strategic priority. Nuclear thermal and nuclear electric propulsion are seen as key enablers for future space operations, including potential missions to the Moon and Mars.
Antares, based in California, has been developing advanced nuclear technologies for space applications. The company's selection by the Air Force highlights the Pentagon's interest in leveraging private-sector innovation to meet defense needs. The Strategic Breakthrough contract is designed to fund high-risk, high-reward projects that could yield transformative capabilities.
While details of the reactor design remain classified, the award signals confidence in Antares' approach. The company has previously worked on compact reactor concepts and has partnered with national laboratories and universities. The new funding will allow Antares to expand its team, procure materials, and conduct critical experiments.
The contract also reflects broader efforts within the U.S. government to revitalize nuclear power for both terrestrial and space uses. In recent years, NASA and the Department of Energy have invested in nuclear thermal propulsion and surface power systems. The Department of Defense, meanwhile, has focused on nuclear power for satellites to enhance maneuverability and resilience against potential threats.
Industry analysts note that space nuclear reactors face technical and regulatory hurdles, including safety concerns and the need for international coordination. However, the potential benefits—such as increased power for radar, communications, and directed-energy weapons—are driving investment. The Air Force's award to Antares is expected to stimulate further private investment in the sector.
Antares has not disclosed a timeline for delivering a prototype, but the contract likely includes milestones for design reviews and testing. The company's progress will be closely watched by both defense officials and the commercial space industry, as success could open the door to broader adoption of nuclear power in orbit.
The award comes as the U.S. seeks to maintain its edge in space amid rising competition from China and Russia. Both countries have announced ambitious space programs, including nuclear-powered spacecraft. By funding Antares, the Air Force aims to ensure that American companies remain at the forefront of this critical technology.
For now, the focus is on turning the reactor concept into a viable system. If successful, Antares' reactor could power a new generation of military and civilian spacecraft, enabling longer missions and more capable payloads. The $161 million contract is a significant bet on that future.
