Principal Thermal Design Engineer

• Collaborate with Mechanical teams to develop passive and active thermal control hardware for the spacecraft including radiators, heaters, heat pipes, and surface coating
• Partner with Avionics teams to develop thermal models and thermal tests for electronic assemblies
• Work with the GNC teams to define and thermally analyze nominal and contingency cases for in-orbit operations of the spacecraft
• Develop and maintain thermal models for spacecraft and sub-components using Thermal Desktop and Ansys
• Interface with vendors and launcher providers to understand their design and translate it into thermal-related requirements
• Automate data analysis to support architectural trades effectively
• Set up and execute thermal testing ranging from development to qualification

• 8+ years of experience with satellite thermal design and analysis
• Demonstrated experience with radiative and conductive thermal modeling of spacecraft systems using Thermal Desktop
• Experience with selection, sizing, and design of thermal control hardware including heat pipes, heaters, stickers, OSR, thermal straps, thermal paints, tapes, MLI, TEC
• Experience with thermal cycling and thermal vacuum testing including predictions, setup, instrumentation and thermal model correlation

• Experience with full-vehicle thermal vacuum testing and model correlation
• Experience with spacecraft thermal design optimized for cost, reliability, performance and manufacturability
• Experience with integrated thermal analysis of spacecraft and rocket
• Experience with solar panel thermal modeling
• Experience with electrical PCBA thermal modeling and thermal interface materials (thermal grease, gap pads, etc.)
• Experience with spacecraft primary radiator design and analysis
• Familiarity with SMC-S016 standard or equivalent
• Experience with Python, C/C++, or Matlab for thermal modeling and automated data analysis

• Base salary range for this role is $175,000 - $295,000 + equity in the company
• Salary will be based on several factors including, but not limited to: knowledge and skills, education, and experience level
• Comprehensive benefits package including paid time off, medical/dental/vision/ coverage, life insurance, paid parental leave, and many other perks

If you don’t meet 100% of the preferred skills and experience, we encourage you to still apply! Building a spacecraft unlike any other requires a team unlike any other and non-traditional career twists and turns are encouraged!

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K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by over $1 billion in total funding from leading investors including Altimeter Capital, ICONIQ, Kleiner Perkins, Lightspeed Venture Partners, Redpoint Ventures, and T. Rowe Price — and with over $1 billion in signed contracts across commercial and US government customers, we're mass-producing the highest-power satellite platforms ever built for missions from LEO to deep space.

The rise of heavy-lift launch vehicles is shifting the industry from an era of mass constraint to one of mass abundance, and we believe this new era demands a fundamentally different class of spacecraft. Engineered to survive the harshest radiation environments and to fully capitalize on today's and tomorrow's massive rockets, K2 satellites deliver unmatched capability at constellation scale and across multiple orbits.

With multiple launches in 2027 and plans to scale to 100 satellites a year, we're Building Bigger — helping develop the solar system and build toward a Kardashev Type II (K2) civilization. If you are a motivated individual who thrives in a fast-paced environment and you're excited about contributing to the success of a high-growth Series D-funded company, we'd love for you to apply.