About the company 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 Structural Engineer at Antares, you will own analysis and dynamics for space nuclear systems, including reactor, spacecraft, radiator, payload, and associated support hardware. This role combines stress analysis, structural dynamics, test planning, and hands-on development support for first-of-a-kind space and lunar reactor programs. You'll work closely with mechanical design, thermal, reactor, manufacturing, test, and systems engineering teams to guide structural architectures from early concept through detailed design, qualification-relevant testing, and integrated hardware development. You will perform first-order analysis, build detailed finite element models, support structural design decisions, derive launch and test loads, and own the analysis-to-test loop for vibration, modal, acoustic, and coupled structural environments. The ideal candidate has strong fundamentals in stress, stiffness, dynamics, and finite element analysis, and can move fluidly between hand calculations, detailed FEMs, design trades, and test execution. This role requires practical engineering judgment, comfort with incomplete requirements, and the ability to define credible structural paths for hardware that must survive launch, space environments, thermal gradients, and nuclear-system integration constraints. Responsibilities Own stress analysis and structural dynamics for space nuclear hardware, including component, assembly, subsystem, and integrated vehicle-level structures. Support mechanical design and perform targeted structural design work for brackets, panels, reactor support structures, radiator structures, payload interfaces, test fixtures, and flight-like development hardware. Perform first-order hand calculations and rapid analytical assessments for stress, stiffness, margin, load paths, bolted joints, welds, bonded joints, fasteners, interfaces, and structural stability. Build, correlate, and maintain finite element models at the component, assembly, subsystem, and integrated system level. Run detailed structural analyses, including static strength, stiffness, modal, random vibration, acoustic, coupled loads, thermal stress, CTE mismatch, fatigue, and shock-related assessments. Support coupled thermal-structural analysis for space nuclear systems, including thermal stress, gradients, interface distortion, alignment effects, and thermomechanical compatibility between dissimilar materials. Define structural analysis plans, load cases, boundary conditions, assumptions, margins, and verification approaches for flight and development hardware. Develop plans for launch loads derivation, test loads definition, qualification strategy, acceptance testing, and structural verification. Work with systems and vehicle teams to interpret launch provider environments, derive subsystem-level loads, and flow loads into design and test requirements. Specify vibration, modal, acoustic, and structural development tests for components, assemblies, and subsystems. Own vibration test planning and execution, including fixture design, instrumentation planning, test article preparation, test procedure development, data review, anomaly resolution, and post-test correlation. Support procurement, commissioning, and operation of in-house vibration test capability, including vibe table requirements, facility integration, test safety, instrumentation, and operating procedures. Participate in design reviews, test readiness reviews, failure reviews, and customer-facing technical reviews, clearly communicating structural risks, margins, model assumptions, and verification status. Drive root-cause investigations for structural failures, test anomalies, model-test correlation gaps, and hardware nonconformances. Develop reusable analysis methods, templates, and workflows that improve structural design speed, consistency, and technical rigor across Antares space nuclear programs. Requirements Bachelor’s degree in Mechanical Engineering, Aerospace Engineering, Civil/Structural Engineering, Engineering Mechanics, or a related technical discipline. 5+ years of experience in structural analysis, stress analysis, structural dynamics, aerospace structures, spacecraft hardware, launch vehicle hardware, mechanical systems, or a related field. Strong fundamentals in solid mechanics, strength of materials, structural dynamics, vibration, fatigue, bolted joints, load paths, stiffness, and stability. Experience building and running finite element models for complex mechanical or aerospace hardware. Experience analyzing static loads, modal response, random vibration, acoustic environments, fatigue, thermal stress, or coupled structural loads. Nice to have Master’s degree or higher in Mechanical Engineering, Aerospace Engineering, Engineering Mechanics, Structural Dynamics, or a related field. Experience with spacecraft, launch vehicles, satellites, payloads, space mechanisms, defense systems, nuclear systems, or other high-reliability aerospace hardware. Experience with launch loads derivation, coupled loads analysis, notching, force limiting, sine vibration, random vibration, acoustic testing, shock testing, modal survey testing, or model correlation. Experience planning, specifying, and executing vibration, modal, acoustic, or structural qualification/development tests. Experience owning vibration test campaigns, including fixture design, accelerometer placement, control strategy, test procedure development, data interpretation, and post-test model correlation. Experience selecting, procuring, commissioning, or operating vibration test equipment, including electrodynamic or hydraulic shakers, slip tables, amplifiers, controllers, fixtures, and instrumentation. Experience with FEA tools such as NASTRAN, FEMAP, Patran, Abaqus, ANSYS, HyperMesh, OptiStruct, Simcenter, NX, or equivalent structural analysis software. Strong familiarity with Python and git-controlled code repositories. Experience with coupled thermal-structural analysis, CTE mismatch, high-temperature structures, refractory materials, radiator structures, heat pipes, reactor support hardware, or nuclear-adjacent mechanical systems. Experience with fatigue, fracture mechanics, creep, buckling, nonlinear contact, preload, bolted joint analysis, bonded joints, weldments, or composite structures. Experience supporting STOP analysis or structural distortion analysis for precision payloads, optical systems, sensors, or thermally sensitive space hardware. Familiarity with aerospace structural standards, launch provider environment definitions, NASA/DoD test practices, or qualification and acceptance test philosophies. Experience developing structural verification plans, analysis reports, test plans, test readiness review packages, and design review materials. Strong practical judgment in early-stage development environments, including the ability to distinguish analysis depth that is necessary for risk reduction from analysis that slows hardware iteration. Requirements Ability to work long hours and weekends as necessary to support critical milestones Benefits Senior Structural Analyst - $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 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.
