Thermal Engineer (Senior)

Responsibilities

• Lead payload thermal design, analysis, and integration from early concept and requirements definition through qualification, launch, and on-orbit operations.
• Own the thermal technical interface with external customers, including requirements definition, interface development, design trades, technical reviews, and resolution of thermal-related issues.
• Develop and maintain spacecraft- and payload-level thermal models using Ansys Thermal Desktop and perform analyses across applicable mission environments.
• Develop and implement advanced passive thermal control solutions, including high-performance heat transport and heat rejection technologies.
• Design and analyze active thermal-fluid systems, including component sizing, system-level performance analysis, and integration with spacecraft thermal architectures.
• Drive thermal design decisions and collaborate with mechanical, systems, avionics, GNC, and other engineering disciplines to ensure vehicle and payload thermal requirements are met.
• Plan and execute thermal subsystem milestones and technical reviews, including SRR, PDR, and CDR.
• Support thermal hardware development, integration, build, and test, including component- and spacecraft-level thermal vacuum testing.
• Correlate test and flight data to thermal models to improve model accuracy and validate thermal performance.

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.

Preferred

• 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.

About the Role

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.

Preferred Qualifications

#LI-MO1

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.

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

Starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays

Competitive 401(k) plan

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 lunch and unlimited snacks

To keep you fueled throughout the day

Vibrant community

Monthly office socials, pickleball tournaments, run club, and gatherings for you and your family

Your dream desk setup

All the tools you need to be your most productive self

World-class Playa Vista office

With the benefit of in-person collaboration with amazing coworkers and flexibility to integrate work and life

Real impact opportunity

Work alongside experts from aerospace, new space, and other cutting-edge industries to make a lasting difference

Additional Information

Compensation ranges are set by role, level, location, and alignment with market data. A candidate's specific level and base pay are determined case by case and may vary with job-related skills, education, experience, technical capabilities, and internal equity. Beyond base salary, full-time hires are also eligible for long-term incentives in the form of stock options, along with medical, dental, and vision coverage and a 401(k) retirement plan.

ITAR Requirements

Apex's work is governed by U.S. export control laws, including the International Traffic in Arms Regulations (ITAR) and the Export Administration Regulations (EAR). To be eligible for this role, applicants must either (1) qualify as a U.S. Person, meaning a U.S. citizen or national, a lawful permanent resident (green card holder), a refugee admitted under 8 U.S.C. § 1157, or an individual granted asylum under 8 U.S.C. § 1158, or (2) be able to obtain the required export authorizations from the U.S. Department of State, the U.S. Department of Commerce, or another applicable U.S. government agency. You can learn more about ITAR here

Equal Opportunity Employer

Apex Technology, Inc. is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Candidates and employees are always evaluated based on merit, qualifications, and performance. We will never discriminate on the basis of race, color, gender, national origin, ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.