Mechanical Engineer - Spacecraft Components and Systems

About the role Muon seeks a Mechanical Engineer to join our team. The ideal candidate can go deep on design and analysis but also has a "systems mindset" and will be a force multiplier collaborating with other disciplines to arrive at an elegant, well-balanced design. Being an early-stage startup with a small team, breadth is extremely important and we expect this person to dive into structural analysis, dynamics, thermal design, supplier management, and everything else associated with the full lifecycle of an electromechanical product. This is an individual contributor role focused on hands-on design, analysis, build support, and test execution for spacecraft mechanical hardware. This position is hybrid and requires working on-site in our San Jose, CA office three days per week. Responsibilities Mechanical Design Create, review, and refine spacecraft component and subsystem mechanical designs in a modern CAD package (SolidWorks), managing small-to-medium assemblies Develop clean-sheet mechanical and structural designs through detailed design, consistent with the risk posture, development velocity, and deployment schedules at Muon Create quick concepts to drive early-phase discussions and inspire the team Influence flight designs to ensure hardware is optimized for manufacturability, assembly, and testability Make economically sound make vs. buy decisions, balancing the need to quickly demonstrate capability while understanding the path to scaled-up constellations Analysis Perform stress and dynamic analyses (hand calculations, simple FEM) to support and inform structural designs, including joint design, fastener sizing, and stiffness analyses Collaborate with structural and thermal analysts to iterate designs for performance and manufacturability Conduct trade studies to evaluate design alternatives and document recommendations Support mass budget tracking and tolerance stack-up analyses for mechanical assemblies Build & Integration Create and maintain build procedures, assembly instructions, and work orders for mechanical hardware Support and oversee technicians during assembly and integration of mechanical components and subsystems Identify and resolve fit, form, and function issues during hardware builds Drive designs toward producibility, considering prototype through production quantity needs Conduct first article inspections (FAIs) and document non-conformances; participate in MRB as needed Test & Verification Design test fixtures and GSE to support development, qualification, and acceptance testing Develop component and subsystem-level test plans and procedures for environmental testing (vibration, shock, TVAC) Specify and integrate test instrumentation (accelerometers, strain gauges, thermocouples, etc.) Execute and support environmental test campaigns; collect, reduce, and analyze test data Document test results and correlate with analysis predictions; recommend design updates as needed Documentation & Configuration Management Create and maintain engineering drawings with proper GD&T, BOMs, and revision control Author and maintain design documentation including trade studies, interface control documents (ICDs), and design rationale Execute ECOs/DCOs and maintain configuration control through PLM systems Document lessons learned from builds and tests to inform future designs Collaboration & Coordination Own delivery of mechanical items and subsystems, coordinating with analysts, avionics, program, thermal, optical, and RF engineers Manage development of mechanical/structural architectures through detailed design in collaboration with cross-functional stakeholders Coordinate with external vendors for part prototyping and development; review vendor deliverables for compliance with requirements Present design status, trade studies, and test results at design reviews Required Qualifications 5 years of experience designing, building, and testing flight hardware in the space industry (or similar: aerospace, autonomous vehic