Systems Engineer, Spacecraft Design & Simulation

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.

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

• 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

Preferred Skills & Experience:

• 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

Base 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: 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.

Vast is developing next-generation space stations and space infrastructure using an incremental, hardware-rich, and low-cost approach. Vast is rapidly developing its multi-module Haven Station 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. 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 in 2027, followed by additional Haven modules. Additionally, the company recently announced Vast Satellite, a high-power satellite product line leveraging its space station components and the heritage of Haven Demo.

Headquartered in Long Beach, California, and with more than 1,000 employees and over a billion dollars in private capital, Vast has built the facilities required to manufacture and operate America’s next space station. The company plans to develop future habitats and systems for the Moon and Mars, dedicated space stations for government partners, and other crewed systems that will unlock the expanding long-term space economy.