Thermal Engineer (Senior) Seen this week

About the Role

Apex manufactures satellite buses at scale for the commercial space industry. You will own thermal engineering for spacecraft platforms that enable earth observation, communications, and beyond.

Your Responsibilities

• Develop and maintain spacecraft-level thermal models using Ansys Thermal Desktop.
• Evaluate and validate thermal analysis results to ensure accuracy and alignment with mission requirements.
• Drive innovation by identifying ways to reduce cost and complexity of legacy thermal subsystems.
• Plan and execute thermal subsystem milestone reviews (SRR, PDR, CDR, MRR).
• Oversee thermal flight hardware integration and ensure quality control during build and test.
• Design, plan, and execute thermal vacuum tests at both component and system levels.
• Correlate test and flight data to thermal models to refine accuracy and performance predictions.
• Collaborate cross-functionally with mechanical, systems, and avionics teams to meet thermal requirements across the spacecraft lifecycle.

What You Need

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or related field.
• 5+ years of experience in thermal engineering, preferably in spacecraft or aerospace systems.
• Proficiency with thermal analysis tools, especially Ansys Thermal Desktop.
• Strong understanding of spacecraft thermal control systems.
• Familiarity with thermal margin definitions per MIL-STD, Aerospace TOR, or vendor command media.
• Proficiency with Siemens NX and Teamcenter.
• Experience with thermal vacuum testing, thermal test instrumentation, and data acquisition systems.
• Working knowledge of 2-phase thermal control systems.
• Strong analytical, problem-solving, and communication skills.
• Ability to critically assess thermal model results and correlate with test or flight data.
• Capable of managing multiple concurrent projects in a fast-paced environment.
• U.S. Persons status is required as this position requires access to export-controlled data.

What We Offer

• Equity in Apex.
• 100% company-paid medical, dental, and vision for you and dependents, plus $100k life insurance at no cost.
• Comprehensive PTO: starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays.
• Competitive 401(k) plan with 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.
• Monthly office socials, pickleball tournaments, run club, and family gatherings.
• Dream desk setup and tools for productivity.
• World-class Playa Vista office with flexibility to integrate work and life.