GPS BASED AUTONOMOUS NAVIGATION STUDY FOR THE LUNAR GATEWAY

This paper describes and predicts the performance of a conceptual autonomous GPS-based navigation system for NASA's planned Lunar Gateway. The system is based on the flight-proven Magnetospheric Multiscale (MMS) GPS navigation system augmented with an Earth-pointed high-gain antenna and, optionally, an atomic clock. High-fidelity simulations, calibrated against MMS flight data and making use of GPS transmitter patterns from the GPS Antenna Characterization Experiment project, are developed to predict performance of the system in the Gateway Near-Rectilinear Halo Orbit. The results indicate that GPS can provide an autonomous, realtime navigation capability with comparable, or superior, performance to a ground -based Deep Space Network approach using eight hours of tracking data per day.