Thermal Engineer III - Spacecraft Programs

Who We’re Looking For Quantum Space is redefining mobility and autonomy in cislunar and geostationary space. Our Ranger spacecraft deliver high delta-V and on-orbit maneuverability that enable customers to access, operate, and persist in orbits previously out of reach. We’re building the infrastructure, vehicles, and operational expertise that connect and protect assets across the Earth–Moon system. 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. Where You’ll Make an Impact 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. What It Takes BS in Mechanical Engineering, Aerospace Engineering, or related field 7+ years of 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 Nice to Have 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 NewSpace environment What you'll get 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 Compensation: $140,000 - 200,000 Annual Salary Additional Requirements To comply with U.S. Government space technology export regulations, including ITAR, applicants must be a U.S. citizen, lawful permanent resident, protected individual per 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State. Apply now. Join us in building the next generation of spacecraft.