Thermal Engineer, In-Orbit Demo Mission (m/f/d)

Focus: You will own the thermal design and validation of TerraSpark's high-power RF wireless power transfer (WPT) payload for our first space-to-Earth power beaming demonstration mission. Your job is to combine first-principles physics with the harsh personality of the orbital environment, and to keep the payload thermally safe and performant in conditions where the hardware would much rather not be. If you enjoy coupling deep analysis with prototyping, build-and-test, and the kind of disciplined simulation that does not flinch when the numbers are inconvenient, this role is for you.

What you'll do:

• Lead the end-to-end thermal architecture for the WPT flight payload: from early design drivers and worst-case assumptions to detailed models, test plans, and design updates, with passive thermal control as the default solution.
• Develop and maintain thermal models (lumped and detailed) of high-power RF amplifiers, electronics, and structures for vacuum, eclipse, and transient orbital conditions, using appropriate analysis tools.
• Define and design passive thermal control solutions that keep hardware within limits during worst-case power and duty cycles, and refine them as thermal technologies and mission constraints evolve.
• Plan and execute thermal test campaigns for the payload and critical subassemblies: test plans, requirements, instrumentation, and correlating real hardware behaviour back to your models so they get sharper over time.
• Review thermal analysis and test outputs from internal work and external suppliers, demanding consistency, quality, and clear conclusions, and manage outsourced analysis activities where needed.
• Present key analysis results, observations, and design implications clearly to the wider team, and influence mechanical, RF, power electronics, and systems designs based on thermal realities rather than thermal hopes.
• Help shape and improve TerraSpark's approach to space environment and physics-based thermal analysis, contributing lightweight processes, tools, and best practices as the team grows.

What you bring:

• MSc or BSc in Mechanical/Aerospace Engineering, Physics, or a related field, with at least 5+ years of relevant experience in thermal engineering for space hardware or similarly demanding electronics/RF systems from other high-stakes industries (nuclear, automotive, aviation, military).
• Deep, first-principles understanding of heat transfer and thermo-physical properties in vacuum and orbital environments, plus familiarity with environmental test methods, requirements, and the test campaigns that go with them.
• Advanced command of thermal analysis techniques, and practical experience taking them from first-order estimates through detailed simulation to test correlation that actually closes the loop.
• Experience with industry-standard thermal analysis software is an advantage.
• Track record designing, analysing, and testing passive thermal control solutions for space-qualified or high-reliability electronics or RF hardware.
• A natural problem-solver with a hands-on mindset: as comfortable in the lab setting up and instrumenting tests as iterating models, and motivated to continuously improve how the team approaches thermal and space-environment analysis.
• Ability to work closely with multidisciplinary teams and external partners, review their thermal work critically yet constructively, and represent the thermal perspective clearly when system-level trade-offs get loud.