Principal Payload Engineer

About Us

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 key member of the Mission Engineering team, you will lead the development of novel effectors, sensors, and instruments needed to unleash nuclear‑enabled missions in all domains. You will serve as a primary technical point of contact for customers and stakeholders during the mission development phase of projects, driving the development mission concepts that are grounded by our ability to project payload performance.

You will lead trade‑off decisions on which payload projects to pursue, as well as “make v. buy” decisions for integrating technologies. Finally, you will be responsible for executing technical projects to develop payloads, with the ultimate goal of building teams to carry out the development of these products to take to market. You understand everything from how on‑orbit nuclear detection is achieved, to bespoke mechanisms for space control.

You will operate at the intersection of engineering, product development, customer program engagement, and mission integration, owning how the complete product is applied to real‑world missions from concept through end of life.

You need to have strong engineering and physics fundamentals – particularly in particle physics, optics, condensed matter physics (materials interactions), remote sensing, thermodynamics, heat transfer, fluid mechanics, energy and power systems, and engineering economics – with demonstrated ability to reason from first principles, develop quantitative models to simulate payload (and thus mission) performance, and maintain high technical rigor across disciplines. You will own product integration into operational end‑user environments.

The ideal candidate is a technical expert who understands space‑domain awareness and space control concepts, yet is able to flex a generalist skillset, comfortably moving between various relevant payload technologies, engineering disciplines, hands‑on analysis, hardware, program execution, and customer‑facing work. They can rapidly develop depth in unfamiliar areas, communicate effectively across engineering teams, and drive ambiguous problems to closure. Experience with DOW, DOE, IC, NASA, or other government sponsors and procurement processes is preferred.

You will be responsible for:

• Lead all aspects of technical product development associated with Antares payloads. Everything from initial ideation and conceptual design to prototyping efforts in the laboratory.

• Regularly build simulation tools and models to develop payload concepts and work directly with Mission Architect on integrating into holistic mission concepts with nuclear and non‑nuclear space vehicles.

• Ideate and propose new development programs to DOW, NASA, IC and DOE funding sources

• Perform market research on possible use cases and operational concepts for future Antares payload systems

• Build out robust…