Systems Engineer, Spacecraft Design & Simulation

Vast • Long Beach, CA

7d • Onsite

About The Position

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. The Systems Engineer, Spacecraft Design & Simulation will 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. 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. 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.

Requirements

• Bachelor's degree in Aerospace Engineering, Mechanical Engineering, Electrical Engineering, Physics, or a related technical discipline
• 4+ years of spacecraft systems engineering or mission analysis experience
• Spacecraft systems engineer with broad subsystem knowledge — you understand power, thermal, ADCS, and orbital mechanics well enough to catch errors in a simulation
• 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
• Rigorous validation mindset — you're the person who asks “how do we know this is right?” and builds the test to prove it
• Comfortable with AI-assisted development workflows
• Generalist background — prior experience at a small-sat company, research lab, or mission design role where you touched multiple subsystems
• Cross-functional collaboration skills — you'll work with every discipline lead to capture their domain knowledge and translate it into validated models
• 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

Nice To Haves

• Able to obtain a security clearance
• Experience building or maintaining spacecraft simulation tools
• Familiarity with orbital mechanics (Kepler solver, J2 perturbations, eclipse geometry)
• Familiarity with CMG dynamics, quaternion attitude propagation
• Experience with data visualization tools or libraries
• Demonstrated use of AI-assisted code generation tools on an engineering project — show us what you built
• Requirements management and verification experience on a spacecraft mission
• Experience with MBSE tools or model-based development methodologies
• Experience scaling engineering tools or analysis workflows across a growing team
• Experience developing validation and verification test suites for engineering tools

Responsibilities

• 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
• 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
• 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
• 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
• Maintain the digital twin as the program's engineering record — requirements, budgets, design parameters, and trade study results live here
• Build and maintain a rigorous validation suite — hand calculations, independent tool cross-checks, edge case analysis, and regression testing for every physics model
• Train and support the engineering team so they can self-serve on trade studies and analysis

Benefits

• company equity
• 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
• other discounts and perks
• exceptional food perks, with snacks, drip coffee & onsite barista, cold drinks, and dinner meals remaining free of charge
• lunch subsidized

What This Job Offers

• Job Type: Full-time
• Career Level: Entry Level