Senior Mission Engineer

About the company

Antares is a nuclear power startup developing small modular reactors (SMRs) using TRISO fuel for deployment at U.S. military bases.

About this role

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 Role As a key member of the Mission Engineering team, you will lead programs across commercial, defense, and space microreactor missions – both on Earth and in space. You will serve as a primary technical point of contact for customers and stakeholders, driving the development, deployment, and application of Antares systems to meet mission needs. You will operate at the intersection of engineering, product development, customer program execution, and mission integration, owning how the complete product is applied to real-world missions from concept through end of life. You'll have strong engineering and physics fundamentals – particularly in thermodynamics, heat transfer, fluid mechanics, energy and power systems, and engineering economics – with demonstrated ability to reason from first principles, develop quantitative models, and maintain high technical rigor across disciplines. You will own product integration into operational end-user environments. The ideal candidate is a technically rigorous generalist comfortable moving between 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 DoD, DOE, NASA, or other government sponsors and procurement processes is preferred.   Roles & Responsibilities - Lead execution of customer-facing and customer-funded R&D programs, owning cost, schedule, quality, contractual compliance, milestone execution, technical deliverables and internal/external reviews to align stakeholders and ensure mission success. - Manage program costs, schedules, quality, and deliverables; translating customer needs into technical requirements; and performing or coordinating the engineering needed to close cross-disciplinary gaps. - Drive product development to ensure Antares systems can be transported, deployed, commissioned, operated, integrated with customer infrastructure, maintained, and decommissioned. - Success in this role requires a generalist mindset, cross-disciplinary problem-solving, and relentless focus on delivering value to our customers. - Own mission-level product integration across the R1 lifecycle, translating customer needs into requirements, interfaces, operational concepts, and product development priorities that ensure the complete system can accomplish its intended mission. - Perform first-principles analyses across disciplines, developing models and tools as needed to evaluate trade spaces, quantify mission impacts, answer mission-level questions, and close technical gaps between subsystem teams. - Ideate and develop new applications and customer missions for Antares technology, supporting RFIs, proposals, white papers, and contract capture with technical concepts, system performance justifications, development roadmaps, and customer use cases. - Lead and contribute to system architecture, interface definition, and technical trade studies, integrating engineering, operational, cost, schedule, and business considerations into product and program decisions. Basic Qualifications: - Bachelor's degree in an engineering discipline (mechanical, electrical, aerospace, nuclear, systems, etc.), physics, or applied science. - Exceptional technical writing and communication skills, with demonstrated ability to synthesize multidisciplinary engineering work into clear customer-facing deliverables. - 5+ years of experience developing or delivering technically complex systems in aerospace, nuclear, energy, automotive, defense, or another mission- or safety-critical environment, with demonstrated ownership of multidisciplinary technical problems and program cost/schedule/technical performance. Preferred Skills and Experience: - Master’s degree or PhD in an engineering field. - Proficiency in Python for numerical/multiphysics work and familiarity with modern toolchains (Git and CI/CD). - Strong foundations in thermodynamics, heat transfer, fluid mechanics, energy conversion and power systems, and engineering economics. - Experience developing, integrating, testing, or commissioning complex hardware or energy systems. - Experience with mission engineering, CONOPS development, system architecture, modeling and simulation, and trade studies. - Experience across one or more adjacent technical domains such as high-temperature systems, turbomachinery, materials and composites, power systems, nuclear, or aerospace. - Experience with government sponsors (DoD, DOE, NASA, USAF/USSF) and government-funded R&D, proposals, or contracting. - Strong interpersonal and collaborative skills, enthusiasm for problem-solving, and a desire to optimize modern nuclear design and operation. - Ability to drive decisions and close ambiguous cross-functional problems despite incomplete information and conflicting constraints. - Experience working in a start-up environment. Additional Requirements - Ability to travel to customer and mission-relevant location