Structures Engineer II

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 Structures Engineer II, you'll design, analyze, and develop critical reactor structures, including the core restraint mechanism, control drum support and mounting systems, primary heat exchanger vessel supports, and other safety-significant structural components. You will ensure these systems meet structural, thermal, and functional performance requirements throughout development, testing, and operation. You will work closely with cross-functional teams to develop first-of-a-kind hardware in a highly constrained, multidisciplinary design environment while supporting prototype fabrication, testing, qualification, and deployment.

The ideal candidate has extensive experience designing complex structural systems in regulated industries and is passionate about solving challenging engineering problems from concept through hardware realization.

Roles and Responsibilities:

• Perform thermal, mechanical, and structural analyses to support the sizing, layout, and optimization of reactor structural components, including the core restraint system, control drum mounting, primary heat exchanger (PHX) vessel supports, and other structural systems as required.

• Define system architecture, operating limits, design margins, and concepts of operation (CONOPS) to ensure reliable performance across all operating conditions.

• Develop engineering documentation, including calculations, specifications, interface definitions, design reports, and technical justifications to support design reviews, verification, and licensing activities.

• Lead the design, fabrication, and execution of component- and system-level testing by developing test articles, test fixtures, instrumentation plans, and validation procedures to demonstrate performance, durability, and life-cycle reliability.

• Collaborate cross-functionally with reactor, thermal, manufacturing, licensing and procurement teams to ensure successful integration of structural systems into the overall reactor design.

• Support supplier selection, technical evaluations, design reviews, and the resolution of manufacturing, assembly, and installation issues.

• Present technical work at internal and external design reviews and provide technical leadership throughout the design, analysis, testing, qualification, and deployment lifecycle.

Basic Qualifications:

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, Nuclear Engineering, or a related engineering discipline.

• 2+ years of professional experience designing, analyzing, and developing structural systems for demanding engineering applications.

• Experience in structural design, including hand calculations, material selection, bolted and welded joint design, load path development, and thermo-mechanical trade studies.

• Experience using finite element analysis (FEA) tools to evaluate structural performance, stress, deformation, fatigue, and thermal loading.

• Knowledge of structural design principles, materials, bolted and welded joints, and load path development.

• Demonstrated ability to work effectively on multidisciplinary engineering teams and communicate technical concepts to a broad range of technical and non-technical stakeholders.

Preferred Skills & Experience:

• Master's degree or higher in Mechanical Engineering, Aerospace Engineering, Civil Engineering, Nuclear Engineering, or a related engineering discipline.

• Demonstrated expertise in structural design, including hand calculations, material selection, bolted and welded joint design, load path development, and thermo-mechanical trade studies.

• Proficiency with structural analysis and s