
At Antares, our long-term mission is to make clean energy abundant from Earth to the Asteroid Belt. We’re fueled by the belief that advanced nuclear energy can strengthen our military, solve the climate crisis, elevate global living standards, and expand humanity's presence in outer space. To achieve our mission, we’re building mass-producible, inherently safe, deployable microreactors that can be used terrestrially, underwater, and in space.
The Antares team hails from SpaceX, the White House, the Pentagon, the Department of Energy, MIT, Rigetti Computing, General Atomics, Relativity Space, Ursa Major, and National Laboratories like Idaho, Oak Ridge, Los Alamos, and Savannah River. Antares has raised over $600M in venture capital from top-tier investors and has hundreds of million-dollars on contract with the military services, NASA, and the Department of Energy.
As a Level I or Level II Mechanical Design Engineer in the Mission Engineering team, you will support hardware design and development associated with nuclear power systems in space and on the surface of the Moon and Mars. As an engineer on the space team, you will be expected to support team members, own development tests, and component design. You will be responsible for your product or deliverable, interfaces to and from other systems, how your hardware fits into the larger system, sourcing, building, testing, and designing improvements for a first of a kind system. You’ll support trades on system layout, interfaces, packaging, working closely with cross-disciplinary teams to refine configurations and close design loops. Your responsibilities will span CAD design, system analysis, design reviews, precise definition of thermal and mechanical interfaces, requirements ownership and decomposition, and manufacturability / scalability of your design.
Mechanical Design Engineer I - $90,000 - $105,000
Mechanical Design Engineer II - $115,000 - $150,000
At Antares, we like to specifically tie each role to our founding document’s set of values–here are the top five cultural values we think you should believe at your core to be successful:
Antares is an Equal Opportunity Employer. Employment decisions are based solely on merit, competence, and qualifications, without regard to race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.
To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.

Energy abundance unlocks progress. It powers missions, grows economies, strengthens national security, and expands what’s possible on Earth and beyond. But in the places where power is most critical, it’s often the hardest to deliver. That’s the problem we’re solving.
At Antares, we’re building compact nuclear microreactors to deliver reliable, mobile energy where it’s needed most: remote military bases, austere industrial sites, and, one day, deep space and underwater missions. The U.S. nuclear industry hasn’t seen true momentum in decades. We’re moving it forward with urgency, humility, and a commitment to building what’s needed now.
Our team includes engineers and operators from SpaceX, Relativity Space, Ursa Major, the White House, MIT, Rigetti Computing, and the U.S. Air Force. Backed by over $130M from top-tier investors, we’re focused on shipping hardware not hypotheticals.