Thermal Engineer
US$145,000 – US$185,000 / yr base salary
Posted 3 Oct 2026
Advertised as “Senior Thermal Engineer - Space”
BranchFactor Summary
The original posting with the fluff stripped out
- Expected experience
- 5+ yrs
- Management level
- Individual contributor
- Contract
- Full-time
| Base salary | US$145,000 – US$185,000 / yr |
|---|
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 Senior Space Thermal Engineer at Antares, you will own and drive the thermal design and analysis of a space nuclear vehicle, including the reactor, spacecraft, and heat rejection systems. You will develop, validate, and anchor thermal models to experimental and test data, using those models to guide early architecture decisions, system-level integration, and hardware design trades.
This role will focus primarily on high-temperature thermal management for space nuclear systems, including reactor heat transport and radiator architectures, while also supporting traditional low-temperature spacecraft radiator design where required. You will work closely with reactor, fluids, mechanical, test, and systems engineers to define thermal management architectures, evaluate heat rejection system configurations, identify data gaps, and mature thermal hardware integration approaches from concept through test-informed design.
Role and Responsibilities
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Construct, own, and validate thermal models for the reactor core, spacecraft, radiator systems, and integrated vehicle thermal response.
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Anchor thermal models to experimental, analytical, and test data wherever available; quantify uncertainty and improve model fidelity over time.
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Identify gaps in thermal, materials, coolant-loop, radiator, and reactor heat-transfer data, and work with test engineers to define, execute, and interpret required tests.
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Develop and analyze space nuclear thermal management architectures, including reactor heat transport, coolant loops, radiator systems, and integrated heat rejection systems.
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Generate, compare, and downselect heat rejection system configurations across performance, mass, temperature, integration, reliability, manufacturability, and operational constraints.