Thermal - Fluids Analyst I​/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.

Formed in 2023, the Antares team hails from Space

X, The White House, MIT, Rigetti Computing, The Air Force, General Atomics, Relativity Space, Ursa Major, and National Laboratories like Los Alamos, Idaho, and Oak Ridge. Antares has raised over $130M in venture capital from top‑tier investors and has over $13M in government funding.

As an analyst at Antares your primary responsibility will be building and running thermal‑fluids models of components and subsystems throughout the reactor core and power conversion system to ensure our designs will meet thermal, mechanical, operational, and performance requirements within the extreme environments of our R1 micro‑reactor. Design engineers will rely on your modeling and technical expertise for iterative design feedback and optimization, while adhering to best practices for DFM (design for manufacturing) and maintaining a rapid pace of development.

Antares aims to maintain close collaboration between testing and analysis teams, and to this end you may often be asked to provide technical support before, during, and after test campaigns. This may take the form of cooperative planning of testing goals, instrumentation requests, root cause analysis in the event of failures, post‑test data review, and model validation/anchoring.

• Assess subcomponent designs for pressure drop, heat transfer capabilities, and other performance characteristics using a combination of hand‑calcs, in‑house tools, and CFD
• Collaborate with designers and responsible engineers to provide guidance on initial sizing, material selection, and design feedback based on analytical results
• Compile detailed documentation of analytical results and communicate key results, assumptions, and limitations to stakeholders throughout the company and external customers
• Provide support to test engineers in the form of collaborative test design, instrumentation selection, and data review to ensure test campaigns provide the necessary data to validate our models
• Develop internal tools and calculators to enable other engineers to quickly and independently perform analytical assessments of their designs without the need for detailed finite element models
• Provide technical mentorship and guidance to other engineers and across teams

• Bachelor's in Mechanical or Aerospace Engineering or similar technical discipline
• Experience building and running CFD models using commercial codes such as Fluent, CFX, and Star‑CCM+, including conjugate heat transfer models and compressible equations of state
• Experience using Computer Aided Design (CAD) software for design modification and model defeaturing (Siemens NX or similar)
• Experience in Python, Mat Lab, VBA, or other scripting language to build and maintain tools and calculators

• Master's in Mechanical or Aerospace Engineering or similar technical discipline
• 3+ years experience performing thermal‑fluids analysis
• Familiarity with 1‑D fluid network tools such as Flownex, Sinda‑Fluint, or RELAP5
• Participation in regulatory qualification or certification programs for safety critical systems in the aerospace or nuclear industry
• Understanding and experience of implementing numerical methods to solve fluid‑dynamic and thermodynamic systems
• Experience working with multiphase fluid & heat transport systems (Heat Pipes, Rankine Cycle Engines, Saturated Cryogenic Storage)
• Familiar with ASME BPVC Section III Div 5
• Experience building and running Finite Element Analysis (FEA) models
• Comfortable in fast‑paced environment with rapid design iteration loops

• Ability to work long hours and weekends as necessary to support critical milestones