Antares, a nuclear power startup based in Redondo Beach, announced in early December that it raised $96 million in series B funding, bringing its total to $130 million.
The round, which is split up into $71 million of new equity and $25 million in debt, was led by Shine Capital with additional participation from Alt Capital, Caffeinated Capital, 53 Stations and Industrious Ventures. Antares will use the debt to help obtain equipment, build out a factory and procure uranium.
Antares is building modular, transportable nuclear reactors to power off-grid locations – from remote corners of the earth to outer space. These microreactors are often considered the next energy generators for rural areas, disaster zones and industrial sites without the need for traditional fossil fuels.
“We observed that the military has unique use cases for nuclear power across Earth and space that the other commercial microreactor developers were not designing around,” said Jordan Bramble, the chief executive of Antares. “… And the large defense primes were unable to service on a cost and schedule that was workable from the department.”
Exploding with possibilities
Antares is one of several companies enjoying a renewed private interest in nuclear energy. The global nuclear energy sector received $2.92 billion so far in 2025, an all-time high according to PitchBook. Ninety percent of that funding went to companies in the U.S.
Perhaps that’s unsurprising. As part of America’s rally to build its first small reactors, the U.S. Department of Energy awarded $800 million in grants in early December to develop more modular reactors that stand alongside 94 large-scale reactors that make up the country’s fleet of nuclear energy generators.
“…America is going to build more energy, not less, and nuclear is central to that mission,” Chris Wright, Secretary of Energy, said in a statement. “Advanced light-water (small modular reactors) will give our nation the reliable, round-the-clock power we need to fuel the president’s manufacturing boom, support data centers and AI growth, and reinforce a stronger, more secure electric grid.”
Future of small nuclear reactors
Few small nuclear reactors are on the market today. Rosatom, the Russia-based company that exports the most civilian nuclear technology, has a singular small modular reactor floating on a remote barge in Siberia. China is the second country to have successfully built and deployed small modular reactors.
Smaller reactors have been heralded as a necessary evolution in the nuclear energy space due to their modularity, perceived lower cost and increased safety. However, the technology is currently too nascent to have its benefits fully demonstrated and proven.
Antares is taking a different approach to solidify itself in a rather nascent time in nuclear energy innovation. The company is focusing squarely on applications where nuclear energy is preferred for its specific capabilities, rather than for being a cheaper alternative to conventional energy sources. The company is primarily focusing on military and space use cases, such as the Fission Surface Power program from the National Aeronautics and Space Administration, which is working with private companies to develop a powerful nuclear reactor on the moon.
“This focus will build our own institutional capability to rapidly design, license, manufacture, and test reactor designs that leverage our core competencies, and ultimately scale into commercial markets with commercial variants that are even more economically competitive,” Bramble said.
