Senior Mechanical / Thermal Engineer - Heat Transfer Systems

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.

Formed in 2023, the Antares team hails from SpaceX, The White House, MIT, Rigetti Computing, The Air Force, General Atomics, Relativity Space, Ursa Major, Ultra Safe Nuclear, and Los Alamos National Laboratory. Antares has raised over $39M in venture capital from top-tier investors and has over $4M in government funding. 

About the Team

As a Heat Transfer Systems Responsible Engineer you will play a critical role in the development, design, and implementation of advanced heat pipe systems for cutting-edge nuclear microreactors. This position requires a deep understanding of thermal engineering and heat transfer in extreme environments, with a focus on reliability, safety, and efficiency. The ideal candidate will drive innovation and ensure the highest standards in nuclear heat pipe technology, contributing to next-generation sustainable energy solutions.

Roles & Responsibilities:

• Lead the design, modeling, and analysis of heat pipe systems, ensuring compatibility with R1’s core design, interfaces, and power conversion systems

• Develop manufacturing methods for prototyping and mass manufacturing

• Develop test articles, stands, and procedures for validating the limits of heat pipe performance and life characteristics

• Interface with core, containment vessel, and primary heat exchanger parts and owners to integrate heat pipes into the overall R1 system

• Define operating procedures and limits for reactor control system integration

• 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

• Minimum of 5+ years of experience in thermal engineering, with a focus on heat pipes or heat transfer systems, preferably in nuclear or high-reliability sectors.

• Proficiency in thermal modeling software (e.g., COMSOL, ANSYS)

• Knowledge of materials science as it applies to alloy selection for heat transfer and structural properties

Preferred Skills and Experience:

• Master’s or PhD in Nuclear Engineering, Thermal Sciences, or Mechanical / Aerospace Engineering

• Demonstrated expertise in heat pipe design, analysis, manufacturing, or test

• Strong understanding of nuclear safety standards, testing protocols, and regulatory requirements

• 5+ years of experience in nuclear thermal or other 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

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.” 

• Craftsmen - We also focus on the inputs. We aspire to high-quality engineering for its own sake. As such, we invest in personal growth, learning, and developing a long-term career path for exceptional individual contributors. We embrace a beginner’s mindset, share knowledge, and never condescend the curious. 

• Loyally Collaborative - Team > Self. We win together. There is nothing more precious than a high-performing team. 

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.