Spacecraft Thermal Engineer

Space Machines Company; Sydney; On-site; AUD 120,000 - 180,000; Full time

Job summary

Space Machines Company in Australia is seeking a Spacecraft Thermal Engineer to analyse, design, and validate thermal control systems for our Optimus Viper spacecraft across LEO to GEO.

You will build thermal models, run analyses of varying fidelity, and translate results into actionable design recommendations while supporting tests, design reviews, and cross-functional collaboration with avionics, structures, propulsion, power, GNC, manufacturing, and AIT.

Responsibilities

• Develop, run, and maintain thermal models (GMM/TMM) of spacecraft and subsystems.
• Support thermal design and sizing of active and passive solutions.
• Perform rapid iteration with hand calculations, spreadsheets, and Python.
• Conduct trade studies on thermal architecture and present conclusions.
• Support thermal testing and participate in chamber campaigns.
• Produce clear thermal analysis reports and design verification materials.

Skills

Thermal analysis

Thermal design

Python

Trade studies

Documentation

Tools

Thermal Desktop

Systema/Thermica

ESATAN-TMS

Job description

About Us

Our mission is to safeguard critical space infrastructure by providing the first integrated security platform to see threats, decide fast and respond at scale. Where spacecraft have traditionally been costly, slow to produce and require extensive effort to coordinate, SMC is developing systems that are produced at scale and operated with human-on-the-loop autonomy to drastically reduce the cost and complexity of orbital operations. As space becomes more congested and contested, the satellites that underpin modern life, including communications, navigation, financial systems, are increasingly exposed. We are developing the vehicles and software to protect them, working with commercial operators and government agencies across allied nations. Our approach is grounded in economics as much as engineering. The Optimus Viper Rapid Response Vehicle delivers genuine mission capability at a fraction of conventional spacecraft cost, designed for high-volume production and rapid deployment across all orbital regimes. Solstice OS, our AI-driven command and control platform, fuses space domain awareness data and automates mission planning and vehicle coordination, allowing smaller teams to manage larger constellations and respond to emerging situations in seconds rather than hours. The future of space depends on assets that can be inspected, monitored and protected in orbit. We are building the technology to make that possible.

Why Join Us

We're a start-up. Things move fast, resources are lean, and we're building as we go. What we offer is opportunity: to learn at speed, grow with the company, and leave your fingerprints on something that's never been done before. At Space Machines Company, engineers, innovators, and problem-solvers join forces to push the limits of what's possible. If you want to build technology designed to protect and power humanity's future in space and see your work make a visible impact. This is where you'll do it.

How We Work

We are builders first. We approach every challenge through a cycle of design, build, test, and refine, making ideas real, learning from results, and improving with each iteration. We challenge assumptions to make sure we're solving the right problems, and we strengthen our solutions through collaboration and feedback. We use process where it adds value and set it aside where it slows us down. There are a lot of firsts here, and we meet them with curiosity and courage. We win as one team.

The Role

As our Spacecraft Thermal Engineer, you will work alongside the Thermal and Mission Systems Lead to analyse, design, and validate the thermal control systems that keep Optimus Viper operating across harsh orbital regimes, from LEO to GEO and beyond. You'll ensure our vehicles not only survive but perform through every mission phase, from launch through end-of-life. You'll spend your time on real projects from the beginning: building thermal models, running analysis cases at varying levels of fidelity, and translating results into clear recommendations that guide design decisions, while also supporting thermal test campaigns, design reviews, and close collaboration with avionics, structures, propulsion, power, GNC, manufacturing, and AIT. This is a unique opportunity to contribute to the fast-paced design, build, and testing of a Rendezvous and Proximity Operations (RPO) capable spacecraft. In this role, you own outcomes from end to end, including:

• Thermal Analysis - Develop, run, and maintain thermal models (GMM/TMM) of spacecraft, subsystems, and equipment using industry-standard tools (such as Thermal Desktop, Systema/Thermica, ESATAN-TMS, or equivalent). You will define hot, cold, and edge cases that drive the design, and correlate models against test and flight data.
• Thermal Design - Support the design and sizing of active and passive thermal control solutions. You will translate analysis into practical hardware recommendations the team can build against.
• Rapid Iteration - Execute hand calculations, spreadsheet models, and Python first-order analysis grounded in first principles. You will apply the right level of fidelity for the question at hand and turn analysis around fast enough to keep pace with fast design cycles.
• Trade Studies & Recommendations - Conduct trade-off studies on thermal architecture, balancing thermal performance against mass, power, cost, manufacturability, operational constraints and schedule. You will present key assumptions, problems, results, and conclusions to the Thermal and Mission Systems Lead and wider team to guide real design decisions.
• Test & Validation - Support and execute thermal testing of our spacecraft and equipment. You will see your work through from analysis to chamber and get real feedback on how the design performs.
• Documentation & Reviews - Produce clear thermal analysis reports, design notes, verification evidence, and review material. You will support internal and external technical reviews, including reviews with customers