Space Mechanical Design Engineering Intern - Summer 2027

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. About the Summer Internship Program Internships at Antares are anything but ordinary. You'll work alongside our team as we design, build, and test fission microreactors built to deliver reliable energy for critical missions on Earth, in space, and underwater. Our interns contribute to real work from day one. Depending on your role, you may touch hardware, write and test software, support manufacturing and operations, or help build the systems that allow Antares to move quickly as we scale. You'll work alongside engineers, operators, and other experts solving challenging problems—and you'll leave your internship with hands-on experience that's difficult to find anywhere else. We work hard, move quickly, and take pride in what we're building. If you're excited to learn by doing and want to contribute to the next generation of nuclear energy, we'd love to have you join us next summer. We will be running two separate cohorts to accommodate students on both semester and quarter schedules: Cohort #1 Monday, May 17 – Friday, August 13 Cohort #2 Monday, June 14 – Friday, September 10 All internship roles are based at our Torrance headquarters and require interns to work onsite five days per week. We will not be considering candidates for remote or hybrid arrangements. Interns will receive a relocation and housing stipend as part of their offer package. About the Role As a Space Mechanical Design Intern, you will contribute to the mechanical design and development of Antares reactor and power systems, with a particular focus on space applications. You will work on hardware ranging from space radiators and power conversion components to reactor mechanical systems, taking projects from early design and manufacturing concepts through integration and testing. You will also evaluate how Antares systems could be deployed across different applications, translating customer operating conditions into technical requirements and concepts of operation. This role offers exposure to both detailed hardware development and the system-level engineering required to deploy nuclear power systems in space and terrestrial applications. Roles and Responsibilities: Design, develop, and test space radiator hardware Develop manufacturing approaches for scaling radiator technology from small test coupons to full-scale hardware Contribute to the development and integration of space power conversion systems Own the design and development of power conversion components such as recuperators, primary heat exchangers, and piping Support overall mechanical integration of space power conversion systems Contribute to reactor mechanical design Perform microgrid analyses, including identifying nominal customer load profiles, outage frequencies, integration with other energy sources, and power distribution requirements Develop reactor deployment assessments and concepts of operation for candidate applications Evaluate external markets, including process heat, to identify potential reactor deployment concepts and customer use cases Translate potential customer applications into technical requirements Expan