Senior Thermal Fluids Analyst
Confirmed on the employer's own hiring board on Oct 30, 2026. First seen by Alion on Oct 22, 2026. Antares Nuclear scores A on the Alion truth index.
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 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.
Roles and Responsibilities:
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
Basic Qualifications:
Bachelor's in Mechanical or Aerospace Engineering or similar technical discipline
5+ years' experience performing thermal-fluid analysis
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, MatLab, VBA, or other scripting language to build and maintain tools and calculators
Preferred Skills & Experience:
Master's in Mechanical or Aerospace Engineering or similar technical discipline
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 a fast-paced environment with rapid design iteration loops
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 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.