Staff-Principal Tooling Design 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. Roles & Responsibilities - Own the design, development, fabrication, qualification, and implementation of tooling and ground support equipment required to manufacture, assemble, test, transport, install, service, and ultimately decommission Antares R1 microreactors. - Work directly with manufacturing, test, reactor hardware, operations, quality, and deployment teams to understand how hardware will actually be built and handled, identify tooling needs, and translate those needs into practical engineering solutions. - Develop tooling concepts from first principles, balancing safety, usability, manufacturability, schedule, cost, reliability, and the constraints of both factory and field environments. - Create detailed 3D CAD models, assemblies, and engineering drawings for fixtures, handling equipment, lifting devices, assembly tooling, test support equipment, transportation fixtures, installation equipment, and other specialized mechanical systems. Siemens NX experience is preferred. - Perform mechanical design and basic engineering analysis necessary to ensure tooling is structurally adequate, stable, safe to operate, and appropriate for its intended loads and environments. - Design tooling with the operator in mind, including ergonomics, access, alignment, tolerance stack-up, repeatability, mistake-proofing, inspection access, maintainability, and efficient integration into manufacturing and test workflows. - Take designs beyond the drawing package by working hands-on with machinists, welders, technicians, suppliers, and engineers to fabricate, assemble, troubleshoot, modify, and commission tooling. - Direct and support the initial use of new tooling on the factory floor and at deployment sites, incorporating operator feedback and observed performance into rapid design improvements. - Develop ground support equipment and handling solutions for large, heavy, sensitive, or high-value reactor hardware, including equipment used for lifting, positioning, alignment, transportation, installation, and removal. - Support integrated reactor and subsystem testing by developing fixtures, test stands, interfaces, temporary structures, and other equipment needed to safely configure and operate development and qualification hardware. - Develop tooling and equipment required for reactor transportation and site deployment, accounting for packaging, shipping, field handling, limited site infrastructure, environmental conditions, and installation sequence. - Partner with deployment and reactor engineering teams to develop tooling concepts and procedures for future maintenance, removal, and decommissioning activities so that lifecycle handling considerations are incorporated into the reactor design early. - Generate and maintain complete engineering definition for tooling, including drawings, bills of material, specifications, load requirements, operating limits, inspection requirements, and supporting documentation. - Work closely with suppliers and internal fabrication teams to source components and manufacture tooling, resolving fabrication issues and making practical design decisions that maintain schedule without sacrificing safety or functionality. - Develop operating instructions, checkout requirements, and safe-use criteria for specialized tooling and support training of technicians and operators responsible for its use. - Participate in design reviews, build readiness reviews, test readiness activities, and field planning to ensure the equipment required to safely execute the work is identified and available before it becomes a schedule constraint. - Identify opportunities to simplify reactor assembly, test, transportation, and installation through improved tooling, automation, mechanization, or changes to the product design itself. - Serve as a hands-on technical owner for tooling throughout its lifecycle, from initial concept through fabrication, use, modification, maintenance, and retirement. Basic Qualifications: - Bachelor’s degree in Mechanical Engineering, Aerospace Engineering, Manufacturing Engineering, or a related technical discipline. - 8+ years of experience designing mechanical hardware, tooling, fixtures, ground support equipment, manufacturing equipment, or similar systems. - Strong 3D CAD skills and experience developing production-quality engineering drawings; Siemens NX experience is preferred but not required. - Demonstrated ability to take mechanical designs from initial concept through detailed design, fabrication, assembly, and implementation. - Experience designing hardware for practical use in manufacturing, assembly, test, installation, maintenance, or field operations environments. - Strong understanding of mechanical design fundamentals, including tolerance stack-ups, fits, fasteners, structural loading, material selection, and design for manufacturing and assembly. - Ability and willingness to support tooling installation, checkout, and operation in both factory and field environments. Preferred Skills and Experience - Experience designing ground support equipment (GSE), lifting and handling equipment, assembly fixtures, transportation fixtures, test stands, deployment equipment, or other specialized tooling for aerospace, nuclear, defense, automotive, heavy industrial, or similar hardware. - Proficiency with Siemens NX, including complex assemblies, detailed drawings, and configuration-controlled mechanical design. - Experience designing tooling for large, heavy, high-value, or geometrically sensitive hardware requiring controlled lifting, positioning, alignment, or installation. - Experience with lifting and rigging equipment, including understanding of load paths, factors of safety, lifting interfaces, and applicable design practices or standards. - Experience performing or reviewing structural calculations or finite element analysis for tooling, fixtures, frames, lifting equipment, or support structures. - Experience supporting integrated hardware testing and developing fixtures, interfaces, temporary structures, or support equipment for test operations. - Familiarity with common fabrication processes including CNC machining, welding, sheet metal fabrication, structural fabrication, additive manufacturing, and commercial off-the-shelf component selection. - Experience commissioning new equipment on a production floor or at a field site and directly supporting its initial operation. - Experience working in a highly regulated or safety-critical industry such as nuclear, aerospace, spaceflight, defense, energy, or medical devices. - Comfortable working in a fast-paced hardware development environment that requires a blend of detailed engineering, hands-on problem solving, and rapid execution. Location - We are located in Torrance, CA in a 145,000 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 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: - 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 were 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 Is - 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 https://www.pmddtc.state.gov/?id=ddtc_kb_article_page&sys_id=24d528fddbfc930044f9ff621f961987.