Senior Mechanical Engineer, Thermal Control Systems

Vast • Long Beach, CA

11d • Onsite

About The Position

At Vast, our mission is to contribute to a future where billions of people are living and thriving in space. We are building artificial gravity space stations, allowing long-term stays in space without the adverse effects of zero-gravity. Our initial crewed space habitat will be Haven-1, scheduled to be the world’s first commercial space station when it launches into low-Earth orbit in 2026. It is part of our stepping stone approach to continuous human presence in LEO. Our team is all-in, committed to executing our mission safely and on time. If you want to work with the most talented people on Earth furthering space exploration for humanity, come join us. Vast is seeking a Senior Mechanical Engineer, Thermal Control Systems , reporting to the Senior Manager, Thermal Control Systems Hardware, to build the fluid and thermal systems that make artificial gravity—and long-term human life in space—possible. You will develop hardware that must operate flawlessly in orbit, leading projects from concept through flight. This is a high-impact role for an engineer who thrives in fast-paced development, embraces technical ownership, and wants their work to directly shape the future of human spaceflight. This full-time, exempt position is based in Long Beach, CA .

Requirements

• Bachelor’s degree in mechanical engineering or a related discipline
• Experience working with fluid systems
• 5+ years of hands-on hardware experience (fabrication, assembly, and/or testing)

Nice To Haves

• 4+ years designing or developing fluid systems or components
• Demonstrated ownership of mechanical or fluid hardware in a fast-paced engineering environment
• Hands-on experience in fabrication, assembly, or test operations
• Expertise in root-cause analysis, test design, and systems-level failure investigation
• Ability to make crisp, principled engineering decisions using first-principles reasoning
• Experience with rotating machinery
• Proficiency in NX and strong application of GD&T and tolerance stack-up analysis
• Background in structural analysis (hand calculations, FEMAP, ANSYS)
• Familiarity with machining, welding, brazing, tube bending, and other manufacturing processes
• Exceptional communication and organizational skills, with the ability to perform in a high-ownership, mission-driven environment
• Ability to travel up to 5%
• Willingness to support occasional evening or weekend work during critical mission phases

Responsibilities

• As a senior technical contributor, you will bring engineering rigor, creativity, and a builder’s mindset to every phase of hardware development.
• Own the architecture, design, and performance of thermal control system hardware, including tubing, fluid loops, trays, and related assemblies.
• Lead the full hardware lifecycle —from early design trades through manufacturing, qualification testing, launch prep, and on-orbit operation.
• Prototype and iterate rapidly , driving development testing that accelerates learning and improves system performance.
• Perform systems engineering analyses and requirement definition , ensuring seamless integration with mechanical, avionics, software, and mission operations teams.
• Lead design reviews with internal partners and external suppliers, delivering clear technical recommendations.
• Ensure manufacturability, reliability, and human-rated safety , translating complex designs into hardware that can be built consistently and perform in space.
• Collaborate closely across disciplines , supporting technicians and manufacturing teams as designs move into production.
• Take ownership of timelines and outcomes , bringing a mission-driven mindset to every deliverable.

Benefits

• 100% medical, dental, and vision coverage for employees and dependents, flexible paid time off for exempt staff and up to 10 days of vacation for non-exempt staff, paid parental leave, short and long-term disability insurance, life insurance, access to a 401(k) retirement plan, One Medical membership, ClassPass credits, personalized mental healthcare through Spring Health, and other discounts and perks.
• We also take pride in offering exceptional food perks, with snacks, drip coffee, cold drinks, and dinner meals remaining free of charge, and lunch subsidized as part of Vast’s ongoing commitment to providing high-quality meals for employees.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Number of Employees: 501-1,000 employees