Senior Systems 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. About the Role You will lead programs across commercial, defense, and real-world microreactor missions—both on Earth and in space. You will serve as the primary point of contact for a broad range of stakeholders, driving the development and deployment of Antares systems to meet mission needs. You'll operate at the intersection of systems engineering and business development, bridging technical product development with operational execution supporting capture and execution of contracts and funding opportunities. You will manage project costs, schedules, deliverables, and translate user feedback into actionable internal requirements. You will be expected to contribute to internal product development to ensure Antares’ systems can meet mission objectives—including deployment logistics, facility interface definition, transportation requirements, commissioning, and decommissioning of nuclear systems.Success in this role requires a generalist mindset, cross-disciplinary problem-solving, and relentless focus on delivering value to our customers. The ideal candidate has direct experience interfacing with, or working within, DoD/DOE and understands government procurement processes, is comfortable with the technical details of complex aerospace or defense systems and can communicate effectively across all associated engineering disciplines. Roles and Responsibilities: Lead delivery for customer-facing programs—owning cost/schedule/quality, contractual compliance, and milestone execution—while driving engineering collaboration across disciplines and internal/external reviews to align stakeholders and ensure mission success. Establish closed-loop requirements management that connects customer feedback to engineering design inputs and maintains alignment with user requirements and intended use cases. Ideate and propose new development programs to DoD and DOE sponsors, and support proposal development and contract acquisition by drafting technical content, interface requirements, operational use case descriptions, and system performance justifications. Perform market/use-case analysis and CONOPS research and develop internal technical roadmaps to ensure product readiness for specific deployments and customer mission needs. Lead and contribute to system architecture and interface specifications for strategic energy applications, ensuring that engineering decisions incorporate business considerations and cost-benefit tradeoffs across design, integration, and delivery. Basic Qualifications: Bachelor's degree in an engineering discipline (mechanical, aerospace, nuclear, systems, etc.), physics, or applied science. 5+ years of experience in complex, safety-critical or defense/aerospace programs with accountability for cost/schedule/technical performance and formal review gates. Qualifications include strong engineering and physics fundamentals—particularly in thermodynamics, energy systems, aerospace, and engineering economics—with demonstrated proficiency in systems-level thinking and high technical rigor across disciplines. Systems engineering proficiency and agile best practices in deep technology, with demonstrated cross-disciplinary systems thinking for complex technical systems. Strong foundations in thermodynamics/thermofluids, energy systems, and engineering economics, with experience developing or integrating hardware in energy, automotive, nuclear, or aerospace. Strong communication and technical writing skills, with pragmatic, business-minded decision-making that links technical choices to commercial outcomes. Preferred Skills & 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) Experience with government sponsors (DoD, DOE, NASA, USAF/USSF) and a track record of winning proposals and contracts or high impact / ROI contributions. Strong interpersonal and collaborative skills, enthusiasm for problem-solving, and a desire to optimize modern nuclear design and operation. Excellent negotiation, conflict resolution, and leadership skills. Leadership experience on a project or research team. Experience working in a start-up environment. Additional Requirements Ability to work long hours and weekends as necessary to support critical milestones. Ability to travel to customer and mission-relevant locations as needed. Ability to obtain a Top Secret or Top Secret SCI clearance is preferred. Salary Range Senior Mission Engineer - $145,000 - $185,000 Location We are located in Torrance, CA in a 322,000 square foot, brand new facility featuring large open spaces for team collaboration, R&D, and production, as well as easy access to the 405, 105, and 110 freeways. Our facility is in the heart of Los Angeles' vibrant emerging tech ecosystem alongside many other high growth startups and enterprises. Culture Think in Systems - Energy and Defense are complex ecosystems with numerous stakeholders with competing priorities, conflicting policies, perverse incentives, and emergent and path-dependent properties. First principles thinking alone is insufficient. Think probabilistically and then take action. “If you want to be certain, then you are apt to be obsolete.” Over-optimizing the components often degrades the system Obsess over the End User - The customer and end user are often not the same. We will never build globally competitive commercial products if we lose sight of our end users and their entire interaction with the product life cycle Be Unconstrained by Convention - Our only limits are the laws of physics. Many, even experts, will say what we are working on is impossible. They said the same about SpaceX reusing rockets. Generationally impactful companies, by definition, must accomplish the seemingly impossible. If it was easy, it would have already been done. Never shy away from a solution because it has never been tried before, and never choose to do something because that’s “how it's always been done” Go Where the Work I s - Never miss a chance to meet a customer, user, or stakeholder face to face, even if that means hopping on a plane. If you can’t make it, find a teammate who can channel your intentions and go in your place. Deep work can be done from anywhere, but we believe teams are built in person, and aim to maximize our time together Operate in the Grey - Embrace nuance in pursuit of truth. Question every fundamental assumption Equal Opportunity 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. ITAR Requirements 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. #J-18808-Ljbffr