Antares Nuclear, a Redondo Beach-based nuclear power startup, is building modular and transportable nuclear reactors that are meant to power hard-to-reach energy deserts, like rural swathes of the world and even outer space.Â
Founded in 2023, the company nabbed $96 million in series B funding in December as the U.S. rallies to build the country’s first small reactor that can compete with those found in Russia and China.
The December funding 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.
In total, Antares has raised around $130 million.
As new startups navigate this renaissance in alternative energy, Antares is taking a different business approach. Several alternative energy companies are focused squarely on applications that will allow them to be cheaper and more environmentally friendly than fossil fuels.
However, Antares is focusing on applications in which nuclear energy is the preferred method due to its specific capabilities. That’s why Antares is currently working closely with the military and aerospace sectors, rather than data centers, said Jordan Bramble, Antares chief executive.
Bramble sat down with the Business Journal to talk more about its business approach and the overall industry landscape.
What was the genesis of your company? How did it come to be?
We founded Antares in 2023 on the belief that our nation’s military and the space economy will benefit greatly from rapidly deployable nuclear energy.
The short answer is that we saw a problem no one was solving correctly. The nuclear industry has spent decades optimizing for the commercial grid.
Meanwhile, the customers who actually need and are willing to pay for nuclear power – the Department of War, NASA, remote industrial assets – were underprioritized. These customers, who need power that works for years in places where nothing else will, are who we founded the company to serve.
Long term, our vision is to make energy abundant from Earth to the Asteroid Belt.
Alternative energy received record-breaking venture funding in 2025. Why do you think that is?
I think we are watching a generational shift in how people think about energy. For decades, the conversation was dominated by constraint. That mindset made sense if you believed the only options were fossil fuels or intermittent renewables. But nuclear changes the equation. It offers abundant, reliable, carbon-free power at a density nothing else can match.
A new generation of investors and founders grew up watching companies like SpaceX make the impossible look inevitable, asking themselves: why can’t we do the same with energy?
People want to build a future where energy is not the limiting factor, where we can power data centers or lunar bases and still have capacity to spare. A critical mass of investors now understands that energy abundance is the path to building the future they actually want to live in.
Your company started a little before the AI data center craze. What was your goal back then? Has it changed much from now?
Our thesis has not changed. We started Antares to build nuclear microreactors for defense and space customers, and that is exactly what we are doing.
The AI data center conversation has validated the broader need for nuclear energy, and that is a good thing. If we execute well, the same reactors we’re building today will lay the groundwork for how we power other applications, but we are not skipping steps to get there.
A lot of people associate the energy hype with AI and data centers. Beyond that, what are some overlooked use cases for a company like yours?
The two we are focused on: space and defense.
I’m extremely bullish on how big the space economy is going to become. If NASA is serious about a sustained presence on the moon, and if we ever intend to reach Mars or even mine asteroids, nuclear energy is the foundation.
The space economy is projected to be worth trillions over the coming decades, and a meaningful share of that value depends on solving the power problem first.
On the defense side, the systems that will define the next era of American military capability all share one constraint: energy. Directed energy weapons, advanced radar, missile defense, autonomous platforms, space-based assets. These are all real, funded programs.
The Pentagon has thousands of installations and assets that need resilient power, and the current approach of relying on the grid and diesel is a vulnerability. That is another enormous market hiding in plain sight.
What are some bottlenecks facing energy startups like yours? This could be related to logistics, supply chain or another part of the ecosystem that hasn’t updated to meet demand.
Because American nuclear power has been stagnant over the past several decades, the real bottlenecks come from the fact that we, as an industry, stopped building. Complex technology requires cycles of build, test, learn, repeat. That requires a fundamentally different approach than what the nuclear industry has done for the past forty plus years.
We’ve built Antares with iteration as a first principle. We build and test components daily. By the time our reactors reach customers, the subsystems have been through more iterations than most nuclear programs complete in their entire history.
The nuclear workforce is also aging, and we need to train the next generation to keep pace with this new era of growth. Building a sustainable nuclear sector means investing in talent pipelines now, which is why we are partnering with universities like the University of South Carolina Aiken to develop talent in regions with strong nuclear roots. We need engineers, operators, and technicians who can build and sustain a fleet of reactors for decades to come.
The U.S. also is lagging behind other nations in its ability to deliver nuclear reactor instrumentation and sensors that can operate in high-temperature radiation environments that stretch beyond the operating conditions of our light water reactors. Instrumentation is an underinvested part of the advanced nuclear supply chain.
