Senior GNC Engineer

Senior Gnc Engineer Benchmark Space Systems, a leader in small satellite propulsion systems and in-space mobility services, is looking for an experienced Senior Gnc Engineer to join our team. In this role you will focus on the software layer of our propulsion systems. This is a hands-on role for highly motivated engineers who don't just design algorithms but ship them. You will implement guidance, navigation, and control algorithms for spacecraft propulsion systems, carry them through hardware-in-the-loop validation, and set the Gnc engineering standards for a growing team. This position is ideal for a self-driven individual with strong attention to detail and the ability to execute multiple tasks simultaneously in a fast-paced environment. This is an on-site role at our Pleasanton, CA office. At Benchmark Space Systems, we're pioneering the future of in-space mobility. Our propulsion technologies provide satellites the ability to maneuver, avoid collisions, and maximize mission potential—all while contributing to a safer, more sustainable space environment. Backed by recent funding and a growing slate of new flight contracts for government and commercial customers, we're building a workplace where bold ideas and passionate people thrive. Engineers, innovators, and problem-solvers at Benchmark tackle some of the toughest challenges in spaceflight, working together to turn cutting-edge concepts into real-world solutions. If you're ready to help shape the next era of spaceflight, there's never been a better time to join Benchmark Space Systems. Measurements of Success/Primary Job Responsibilities: Design and implement Gnc flight algorithms for spacecraft propulsion systems (chemical and electric), including closed loop burn execution, thrust, delta-v estimation, burn targeting, cutoff logic, and trajectory correction maneuvers. Own the Gnc flight code: architecture, implementation, review standards, configuration management, and verification evidence. Develop and maintain 6 degrees of freedom simulation capability for burn execution and dispersion analysis across multiple programs. Perform stability analysis of control loops (classical margins, disturbance and slosh interaction, actuator/sensor dynamics) and document it to flight-review standards. Define hardware-in-the-loop test campaigns: what to test, pass/fail criteria, fault injection cases, and test procedures. Validate flight software against simulation truth models and HIL results; close the loop between analysis, code, and test. Support mission design reviews (PDR/CDR) with Gnc analysis products: pointing budgets, execution-error models, and dispersion results. Mentor and guide other engineers in Gnc best practices, code quality, and verification discipline. Contribute to the evolution of our Gnc codebase and toolchain. Education and/or Experience: Bachelor's degree in aerospace engineering, mechanical engineering, electrical engineering, physics, or related field.5+ years of Gnc experience on space vehicles, with demonstrated ownership of algorithms from design through implementation and test. Strong proficiency in MATLAB/Simulink, including model-based design of flight algorithms. U.S. Person Requirement: Due to the nature of the work and access to export-controlled information, applicants must qualify as a U.S. Person under U.S. export control laws. Visa sponsorship is not available for this position now or in the future. Knowledge, Skills, and Abilities: Solid foundation in control theory and stability analysis (frequency- and time-domain methods, robustness margins).Working knowledge of spacecraft attitude dynamics, orbital mechanics, and propulsive maneuver design. Experience validating Gnc software through hardware-in-the-loop testing, including defining test objectives and criteria. Familiarity with flight software frameworks (cFS, F´) and real-time operating systems. Ability to write clear technical documentation and present analysis at design reviews. What makes you stand out: Experience writing flight or embedded software in C or Rust. Experience with propulsion-specific Gnc: finite-burn effects, thrust/Isp uncertainty, propellant slosh, optimal jet select. Experience with both chemical and electric propulsion control (long-duration low-thrust guidance a plus).Experience with strapdown navigation, IMU error modeling, and sensor fusion. Monte Carlo and linear covariance dispersion analysis experience. GMAT, STK, FreeFlyer, or equivalent astrodynamics tooling. Prior experience as a technical lead or mentor on a small team. Experience supporting government programs (NASA, DoD, SBIR/STTR).