Thermal Engineer III - Spacecraft Programs

Thermal Engineer III - Spacecraft Programs

Rockville, MD or Hawthorne, CA

Quantum Space is redefining mobility and maneuverability in space. Our high-mobility spacecraft platforms support national security, civil, and commercial missions with unmatched flexibility and propulsion capability. We build fast and iterate quickly.

We are seeking a Senior Spacecraft Thermal Engineer to lead the development, implementation, and validation of thermal control solutions for our spacecraft platforms. In this high-impact role, you will own major aspects of spacecraft thermal design, analysis, and verification, working closely with a fast-moving team of engineers and scientists to shape the future of in-space systems.

This role is for an experienced technical leader who thrives in a startup-paced environment, can take broad responsibility for thermal system performance, and can mentor junior engineers while also rolling up their sleeves for hands-on integration and testing.

• Lead development of high-fidelity spacecraft thermal models for prediction of on-orbit performance
• Own spacecraft-level thermal architecture, including active and passive thermal control design
• Review, refine, and correlate as-built thermal models and vendor-supplied thermal documentation
• Provide expert recommendations to mitigate thermal risks across spacecraft lifecycle phases
• Collaborate closely with mechanical, electrical, and systems engineering teams to ensure spacecraft designs meet thermal requirements
• Support thermal vacuum (TVAC) test planning, execution, correlation, and troubleshooting
• Mentor and guide junior thermal engineers; establish best practices and processes for modeling, analysis, and documentation
• Develop tools, workflows, and standards within the thermal ecosystem to improve efficiency and repeatability of future programs
• Generate simplified models, thermal environments, and interface documentation for suppliers and customers
• Review and approve component and assembly designs for thermal flight readiness
• Produce engineering content and analyses for design reviews, test readiness reviews, and verification reports
• Support integration, test, and launch-site operations as the subject-matter expert for spacecraft thermal performance

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or related field
• 7+ yearsof relevant thermal engineering experience (spacecraft strongly preferred)
• Advanced proficiency in Thermal Desktop, SINDA/FLUINT, or equivalent thermal analysis tools
• Experience with spacecraft flight hardware, integration, and thermal vacuum testing
• Familiarity with NASA, commercial, and industry standards for spacecraft design
• Demonstrated experience correlating thermal models with test data
• Ability to lead technical efforts and operate with a high degree of autonomy

• Experience with spacecraft operations, thermal limits, and anomaly resolution
• Knowledge of thermal coatings, adhesives, multilayer insulation (MLI), and related materials
• Exposure to electrical component thermal modeling and PCB thermal behavior
• Experience with heat pipes, loop heat pipes, radiators, and advanced thermal hardware
• Understanding of orbital dynamics and thermal environments across varying mission profiles
• Prior experience in a fast-paced startup or New Space environment

• Ownership – Lead spacecraft thermal architecture end-to-end, from modeling to flight readiness.
• Innovation – Develop advanced thermal solutions and shape next-gen modeling and test workflows.
• Impact – Ensure spacecraft survive and perform in space, directly influencing mission success.
• Growth – Expand your technical reach while mentoring engineers and collaborating across teams.
• Compensation – Competitive salary, equity, and comprehensive benefits, including medical, dental, vision, generous leave, HSA, 401(k) matching, and equity sharing.

Location:Rockville, MD or Hawthorne, CA

The salary range for this role is an estimate based on a wide range of compensation factors. Actual salary offer may vary based on (but not limited to) work experience, education and/or training, critical skills,…