Senior Mechanical Engineer, Thermal Control Systems

At Vast, our mission is to contribute to a future where billions of people are living and thriving in space. Vast is developing next-generation space stations to ensure a continuous human presence in space for America and its allies, enabling advanced microgravity research and manufacturing, and unlocking a new space economy for government, corporate, and private customers. Using an incremental, hardware-rich and low-cost approach, Vast is rapidly developing its multi-module Haven Station. Haven Demo's 2025 success made Vast the only operational commercial space station company to fly and operate its own spacecraft. Next, Haven-1 is expected to become the world's first commercial space station when it launches, followed by additional Haven modules to enable permanent human presence by 2030. 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.ResponsibilitiesAs 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.Minimum QualificationsBachelor's degree in mechanical engineering or a related disciplineExperience working with fluid systems5+ years of hands-on hardware experience (fabrication, assembly, and/or testing)Preferred Skills & Experience4+ years designing or developing fluid systems or componentsDemonstrated ownership of mechanical or fluid hardware in a fast-paced engineering environmentHands-on experience in fabrication, assembly, or test operationsExpertise in root-cause analysis, test design, and systems-level failure investigationAbility to make crisp, principled engineering decisions using first-principles reasoningExperience with rotating machineryProficiency in NX and strong application of GD&T and tolerance stack-up analysisBackground in structural analysis (hand calculations, FEMAP, ANSYS)Familiarity with machining, welding, brazing, tube bending, and other manufacturing processesExceptional communication and organizational skills, with the ability to perform in a high-ownership, mission-driven environmentAdditional RequirementsAbility to travel up to 5%Willingness to support occasional evening or weekend work during critical mission phasesPay RangeSenior Mechanical Engineer: $135,800 - $176,400Pay Range: California$135,800—$176,400 USDCOMPENSATION AND BENEFITSBase salary will vary depending on job-related knowledge, education, skills, experience, business needs, and market demand. Salary is just one component of our comprehensive compensation package. Full-time employees also receive company equity, as well as access to a full suite of compelling benefits and perks, including: 100% medical, dental, and vision coverage for employees and dependents, generous paid time off; up to 20+ days of vacation for exempt staff and up to 10+ days of vacation for non-exempt staff with the ability to cash-out unused vacation annually, paid parental leave, short and long-term disability insurance, life insurance, access to a 401(k) retirement plan, 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 & onsite barista, 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.U.S. EXPORT CONTROL COMPLIANCE STATUSThe person hired will have access to information and items subject to U.S. export controls, and therefore, must either be a "U.S. person" as defined by 22 C.F.R. § 120.62 or otherwise eligible for deemed export licensing. This status includes U.S. citizens, U.S. nationals, lawful permanent residents (green card holders), and asylees and refugees with such status granted, not pending.EQUAL OPPORTUNITYVast is an Equal Opportunity Employer; employment with Vast is governed on the basis of merit, competence and qualifications and will not be influenced in any manner by race, color, religion, 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.