The full Potential of an Autonomous GNSS Signalbased Navigation System for Moon Missions

Lunar exploration is considered to be one of the great capstones for the space industry over the next years. The exciting prospective of exploiting the Moon’s potential, both for scientific and economic growth, is consolidated and structured within international agency initiatives, such as the ESA/SSTL Lunar Pathfinder or NASA Artemis program. This growing momentum opens the door to the exploration of new technologies and techniques, with the aim of improving autonomy and robustness of space systems for a wide range of cis-lunar scenarios. The present research is aimed to perform a representative, comprehensive and detailed end-to-end assessment of what are the navigation performance achievable by an autonomous GNSS navigation system for various Moon mission scenarios. Features such as GNSS emitters 3D gain patterns, dual-frequency high sensitivity Moon-aimed GNSS receiver, highly representative dynamics and clock models, real GNSS orbits files, Broadcast Ephemeris, navigation message demodulation and ad hoc Extended Kalman Filter are taken into account simultaneously, in a tailored high fidelity simulator. It will be demonstrated that not only unutilized Earth-GNSS signals reaching the Moon can be acquired and tracked, but also utilized to reach navigation error as low as 50-100 m in terms of Root Mean Square (RMS) 3D error, depending on the simulated scenario. This work has been performed as a part of the ESA activity NAVISP-EL1-023 “Earth-Moon Navigation: System Study and development of a high-sensitive spaceborne receiver”.