Principal Spacecraft Guidance, Navigation & Control Engineer

Who We're Looking For Quantum Space is redefining mobility and maneuverability in space. Our high-mobility spacecraft platforms support national security, civil, and commercial missions with unmatched flexibility and propulsion capability. We build fast and iterate quickly. We are seeking a Principal Spacecraft Guidance, Navigation & Control Engineer to serve as the technical authority for the GNC subsystem across multiple spacecraft programs, leading architecture, design, procurement, integration, and verification. Where You'll Make an Impact Own the end-to-end GNC/ACS architecture from concept development through flight operations. Own GNC subsystem level requirements. Lead spacecraft attitude and control system design, including actuator sizing, sensor selection, control authority, and momentum management strategy. Define and implement control laws for high-ΔV maneuvering, precision pointing, station-keeping, and proximity operations. Architect state estimation frameworks (EKF/UKF, sensor fusion pipelines, covariance management) for robust on-orbit performance. Develop and maintain high-fidelity 6DOF spacecraft simulation environments for analysis, trade studies, verification, and anomaly resolution. Establish GNC verification and validation strategy across analysis, SIL/HIL, hardware integration, and flight test. Support propulsion-coupled dynamics modeling, including thrust misalignment, slosh effects, and flexible-body considerations as needed. Lead GNC participation in system-level reviews (MCR, SRR, PDR, CDR, TRR) and serve as the primary technical voice for the discipline. Analyze flight telemetry and test data to assess performance, diagnose anomalies, and drive configuration or algorithm updates. Define safe-mode, fault management, and degraded control strategies in partnership with FSW and systems engineering. Mentor and manage GNC engineers, establishing best practices, code standards, simulation frameworks, and technical rigor across the team. Support early-orbit operations and critical mission phases as required. What It Takes B.S., M.S., or Ph.D. in Aerospace Engineering, Mechanical Engineering, Electrical Engineering, Robotics, or related field. 15+ years of experience in spacecraft GNC/ACS development, including full lifecycle flight programs. Demonstrated ownership of a spacecraft attitude and/or orbit control system through design, integration, and flight. Deep expertise in rigid-body dynamics, orbital mechanics, estimation theory, and modern control methods. Strong experience with thruster-based ACS architectures and propulsion-coupled control systems. Proven ability to independently architect GNC systems and make system-level trade decisions. Experience implementing flight algorithms in C++, Python, or MATLAB/Simulink, with awareness of real-time constraints. Experience integrating GNC with flight software and avionics, including SIL/HIL validation.…