Vast develops commercial space stations to support sustained human activity, research, and manufacturing in low-Earth orbit and beyond.
<div class="content-intro"><p>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.</p></div><p>Vast is seeking a <strong>Systems Engineer, Spacecraft Design & Simulation</strong> to own the spacecraft simulation toolchain that is the foundation of our mission factory — the software infrastructure that will enable us to scale from our first 10-satellite demo launch to hundreds of spacecraft per year. </p> <p>This will be a <strong>full-time</strong>, <strong>exempt</strong> position located in our <strong>Long Beach</strong> location. </p> <p><strong>About the role:</strong></p> <p>We're building a mission factory — software infrastructure that dramatically reduces the time from customer contract to payload on orbit. The foundation is a simulation and digital twin toolchain that serves as the primary engineering record. Requirements, budgets, design parameters, and trade study results all live in this toolchain. It includes spacecraft power/thermal/ADCS simulation, orbital constellation analysis, communications link budgets, and actuator trade studies. This is model-based systems engineering as it should work — requirements, budgets, and design parameters live in executable models that compute and validate, not in static documents. A working prototype exists today — you'll evaluate it, determine whether to extend it or redesign it, and own the toolchain as we scale from our first 10-satellite demo launch to hundreds of spacecraft per year.</p> <p>This is a spacecraft systems engineering role, not a software engineering role. You define the governing equations, boundary conditions, and expected behavior for each model. You build and maintain a rigorous validation suite — hand calculations, independent tool cross-checks, and edge case analysis — that serves as the quality gate for every change. We use AI code generation tools to accelerate implementation, but the engineering judgment, validation methodology, and physics expertise are yours.</p> <p><strong>Responsibilities: </strong></p> <ul> <li>Own and evolve the spacecraft design, simulation, and digital twin toolchain — power, thermal, ADCS, orbital mechanics, constellation coverage, link budgets, mass and design margin tracking</li> <li>Make the toolchain the hub of the engineering organization — every discipline (thermal, GNC, power, structures) should be able to run trade studies and assess design changes quickly as the program evolves</li> <li>Drive design trades and architecture decisions through analysis — your models are how the team knows whether the power budget closes, whether the thermal architecture works, and whether we meet customer requirements</li> <li>Enable rapid iteration as customer requirements and the design evolve — the toolchain must keep pace with the program so engineers can assess impact immediately, not wait weeks for analysis</li> <li>Maintain the digital twin as the program's engineering record — requirements, budgets, design parameters, and trade study results live here</li> <li>Build and maintain a rigorous validation suite — hand calculations, independent tool cross-checks, edge case analysis, and regression testing for every physics model</li> <li>Train and support the engineering team so they can self-serve on trade studies and analysis</li> </ul> <p><strong>Minimum Qualifications:</strong></p> <ul> <li>Bachelor's degree in Aerospace Engineering, Mechanical Engineering, Electrical Engineering, Physics, or a related technical discipline</li> <li>4+ years of spacecraft systems engineering or mission analysis experience</li> <li>Spacecraft systems engineer with broad subsystem knowledge — you understand power, thermal, ADCS, and orbital mechanics well enough to catch errors in a simulation</li> <li>Strong analytical skills — you can set up a hand calculation for a thermal equilibrium problem, a power budget across an orbit, or a pointing error budget</li> <li>Rigorous validation mindset — you're the person who asks “how do we know this is right?” and builds the test to prove it</li> <li>Comfortable with AI-assisted development workflows</li> <li>Generalist background — prior experience at a small-sat company, research lab, or mission design role where you touched multiple subsystems</li> <li>Cross-functional collaboration skills — you'll work with every discipline lead to capture their domain knowledge and translate it into validated models</li> <li>Comfortable reading and reviewing code — you don't need a software engineering background, but you should be able to understand what code is doing and catch errors</li> </ul> <p><strong>Preferred Skills & Experience:</strong></p> <ul> <li>Able to obtain a security clearance</li> <li>Experience building or maintaining spacecraft simulation tools</li> <li>Familiarity with orbital mechanics (Kepler solver, J2 perturbations, eclipse geometry)</li> <li>Familiarity with CMG dynamics, quaternion attitude propagation</li> <li>Experience with data visualization tools or libraries</li> <li>Demonstrated use of AI-assi