GNSS Navigation and Estimation Engineer

Location: Broomfield, CO

Department: Guidance, Navigation, and Control

What You’ll Do:

• Design and implement a high-accuracy, real-time onboard orbit estimator for a VLEO spacecraft using EKF or equivalent nonlinear filtering approaches; incorporate dynamic force modeling (gravity, drag, SRP), atmospheric drag state estimation, and reprocessing of raw GNSS measurements (code and carrier phase where applicable).
• Develop and maintain the dynamic process models used in both real-time filtering and short-horizon prediction, including uncertainty propagation and covariance realism analysis suitable for maneuver planning and conjunction inputs.
• Design and validate short-term orbit prediction methods (propagation, smoothing, covariance growth characterization) and quantify prediction error during high-drag and geomagnetic storm conditions.
  Support low-thrust operations by:
  • Modeling finite-burn dynamics within the estimator,
  • Performing maneuver reconstruction and thrust parameter estimation,
  • Contributing to steering law and guidance design in close coordination with GNC.
• Analyze orbit–attitude–drag coupling in VLEO and incorporate those effects into estimation and prediction models.
• Generate and own robust, testable C/C++ flight software for real-time orbit determination, with strong attention to numerical stability, covariance integrity, and diagnosability.
• Build and maintain ground-based validation and regression infrastructure, including closed-loop simulation, measurement replay, Monte Carlo campaigns, and hardware-in-the-loop testing with GNSS receivers and antenna systems.
• Provide technical support for GNSS spaceflight hardware integration, including measurement modeling, command and telemetry integration, calibration analysis, and anomaly triage.

Your Ideal Skills and Experience:

• Bachelor’s or Master’s degree in Aerospace, Electrical, Mechanical Engineering, Physics, or related field.
• Strong C/C++ skills for flight software development, including numerical methods, floating-point stability, and deterministic behavior on embedded processors.
• Proficiency in Python for analysis, simulation, and test automation.
• Hands-on experience with nonlinear state estimation (EKF/UKF, smoothing, batch least-squares, or factor-graph methods) and strong numerical linear algebra fundamentals.
• Familiarity with common GNSS formats and products (RINEX, SP3, IONEX, differential code bias, and related bias products) and correction ingestion pipelines
• Deep understanding of GNSS measurement modeling (code and carrier phase), bias handling, and real-world sensor pathologies.
• Solid knowledge of GEO/MEO/LEO/VLEO orbital perturbations (gravity harmonics, drag variability, SRP) and their representation in dynamic models.
• Experience with covariance propagation, filter consistency testing (NEES/NIS), and operational health monitoring.
• Experience integrating GNSS receivers, antennas, and optionally IMUs; familiarity with hardware-in-the-loop validation is strongly preferred.
• Experience with control theory and guidance for low-thrust or drag-modulated flight is a plus.
• Experience designing regression tests, Monte Carlo campaigns, and closed-loop simulation environments.
• Comfort leveraging modern AI-assisted development tools with strong verification discipline and traceability.

Even if you feel like you don’t meet all of the qualifications, we encourage you to apply! Research shows that while men apply to jobs where they meet an average of 60% of the criteria, women and other marginalized people tend to only apply when they meet 100% of the qualifications.

Salary Range:

$130,000 - $155,000 per year