Sr. GNC Orbit Controls Engineer

Xona is the navigational intelligence company bringing real-time, centimeter-level certainty to any device, anywhere on Earth. With Pulsar – the world’s most advanced PNT satellite infrastructure in Low Earth Orbit – Xona will offer a future-proof, backwards-compatible global positioning system optimized for absolute precision, superior power, and robust protection. We're looking for a Sr. GNC Orbit Controls Engineer to design and implement the algorithms and onboard software that handle orbit determination, guidance, maneuver execution, and post-maneuver analysis to deliver safe, efficient, and highly automated station-keeping and disposal. We’re building the software that keeps our spacecraft exactly where they need to be. WHAT YOU’LL DO - Develop open-loop and closed-loop controllers for RAAN and LTAN control, altitude management, station-keeping, and end-of-life disposal - Implement and maintain onboard orbit propagators, select and validate integrators, and ensure numerical consistency with ground truth - Build and validate orbit determination pipelines using EKF or UKF with GNSS, and manage navigation readiness and covariance gating for maneuvers - Design burns and long-arc trajectories, and optimize delta V and timelines under comm visibility, power and thermal, and operations constraints - Plan and execute electric-propulsion long burns, including throttle profile generation, power and duty-cycle scheduling, thermal considerations, ignition and re-ignition logic, progress monitoring, and correction strategies - Coordinate burn pointing and wheel momentum strategy with ADCS - Maintain numerically consistent MATLAB and C++ simulators, create Monte Carlo campaigns, run SIL and HIL tests, and perform post-maneuver reconstruction REQUIRED QUALIFICATIONS - You are strong in orbital mechanics and simulation and have implemented onboard propagators with perturbation models and integrators on flight targets - You have built production guidance, control, or navigation software in C and C++, and use MATLAB and Simulink for analysis, modeling, and test-vector generation - You have designed RAAN and LTAN control strategies in open-loop and closed-loop forms and validated them in high-fidelity sims or flight - You have executed or supported real maneuvers and can reconcile plan versus truth with post-burn estimation - You are comfortable at the ADCS and propulsion interface for burn pointing and momentum management DESIRED QUALIFICATIONS - Master’s or Ph.D. in Aerospace Engineering, Control Systems, Applied Physics, or a related field - Hands-on electric propulsion experience including thrust modeling and calibration, long-burn guidance, duty-cycle planning, and thermal constraints - Experience with orbit propagation algorithms - Trajectory design and optimization expertise - Emphasis on code quality and reliability with unit and integration testing, SIL and HIL, and experience on embedded RTOS or embedded Linux targets - Familiarity with CCSDS ephemeris and attitude formats For U.S. Roles: To comply with U.S. Government space technology export regulations, applicant must be a U.S. citizen, lawful permanent resident of the United States (i.e. Green Card holder), or other protected individual as defined by 8 U.S.C. 1324b(a)(3). For U.K. Roles: To comply with U.K. regulations, this role requires Baseline Personnel Security Standard (BPSS) checks, and successful candidates must be eligible to obtain UK Security Clearance (SC). For Canada Roles: Successful candidates must obtain and hold a security clearance at the reliability status level, and pass security assessment for the Canadian Controlled Goods Program (CGP) and ITAR. We celebrate diversity and are committed to creating an inclusive environment for all employees. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or veteran status.