Senior Thermal Engineer

Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases, more companies launching payloads to space continue to emerge. For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles. Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more. We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.

Apex is seeking a Senior Thermal Engineer to own the thermal design and performance of our spacecraft from concept through flight. In this role, you’ll solve complex thermal challenges across the vehicle, develop and validate spacecraft level thermal models, and directly influence hardware design and mission performance. You’ll work hands-on with flight hardware and partner across engineering teams to take thermal systems from early design through integration, test, launch, and on orbit operations.

Develop and maintain spacecraft-level thermal models using Ansys Thermal Desktop. Perform thermal analyses to evaluate spacecraft performance across mission environments. Develop thermal control solutions and drive thermal design decisions across spacecraft systems. Plan and execute thermal subsystem milestone reviews, including SRR, PDR, and CDR. Support thermal flight hardware integration, build, and test. Design, plan, and execute thermal vacuum testing at the component and spacecraft level. Correlate test and flight data to thermal models to improve model accuracy and performance predictions. Collaborate with mechanical, systems, avionics, and other engineering teams to meet spacecraft thermal requirements.

U.S. Person status is required as this position requires access to export-controlled data. Bachelor’s degree in Mechanical Engineering, Aerospace Engineering, or a related field. 5+ years of experience in thermal engineering or analysis. Experience with thermal modeling and analysis tools. Strong understanding of heat transfer and thermal engineering fundamentals. Strong analytical and problem-solving skills with the ability to work in a fast-paced environment.

Experience with spacecraft or aerospace thermal systems. Proficiency with Ansys Thermal Desktop. Experience designing spacecraft thermal control systems. Experience with thermal vacuum testing, instrumentation, and data acquisition. Experience correlating thermal models with test or flight data. Familiarity with spacecraft thermal margin standards and requirements. Working knowledge of two-phase thermal control systems. Experience with Siemens NX and Teamcenter. Why Join Apex? Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup that has raised more than $500M in funding, and we invest heavily in our people from day one.

For Full-time Employees: Shared upside: Receive equity in Apex, letting you benefit from the work you create Best-in-class healthcare: 100% company-paid medical, dental, and vision for you and your dependents, plus $100k life insurance at no cost Comprehensive PTO package to reset and recharge - starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays Competitive 401(k) plan with generous matching - 100% match on first 3%, 50% on next 2% 8 weeks paid parental leave plus childcare reimbursement up to $350/day for work-related travel Daily catered