Thermo - Mechanical Design Engineer - Heat Pipes

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 Team As a Thermo-Mechanical Design Engineer, you will play a key role in the development, design, qualification, and deployment of advanced heat pipe systems for cutting-edge applications. You will work closely with the Heat Pipe Responsible Engineer and cross-functional teams to mature technologies from concept through production. The ideal candidate will drive innovation and ensure the highest standards in heat pipe technology, contributing to next-generation sustainable energy solutions. This role is required to be onsite in Torrance, CA. Roles and Responsibilities: - Perform design, modeling, and analysis of heat pipe systems, ensuring compatibility with interfaces in their intended applications - Support development of manufacturing methods for prototyping and mass manufacturing of heat pipes - Support development of test articles, stands, and procedures for validating the limits of heat pipe performance and life characteristics - Coordinate with internal teams and external stakeholders to drive the execution of customer requirements into delivered hardware products - Define operating procedures and limits for heat pipes to inform end users of performance envelope - Investigate heat pipe failure and define reliability limits; integrate fixes rapidly Basic Qualifications: - Bachelor’s degree in Mechanical / Aerospace Engineering, Nuclear Engineering, or a related physics-based field - 2+ years of experience in engineering, with a focus on thermal or heat transfer systems - Demonstrated experience with thermal modeling software (e.g., COMSOL, ANSYS) Preferred Skills & Experience: - Master’s in Nuclear Engineering, Thermal Sciences, or Mechanical / Aerospace Engineering - Knowledge of materials science as it applies to alloy selection for heat transfer and structural properties - Demonstrated knowledge in simulation of high temperature 2-phase flow fields - Demonstrated expertise in heat pipe design, analysis, manufacturing, and test - Strong understanding of nuclear safety standards, testing protocols, and regulatory requirements - 2+ years of experience in high temperature (500°C+) systems, including prior work with heat pipe technology - Experience with sodium purification and material handling - Exceptional communication skills to work effectively across teams and convey technical information to non-specialists Additional Requirements: - Ability to work long hours and weekends as necessary to support critical milestones. 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 stake…