Assessment of Lunar User PVT Performances Tightly Coupling Moonlight Signal with IMU Measurements

With the renewed interest in lunar exploration, evidenced by the increasing number of planned missions over the past decade, space agencies are investing in dedicated lunar communication and navigation systems, such as the European Space Agency’s (ESA) Moonlight Lunar Communication and Navigation System (LCNS), to support various types of missions. Other space agencies, such as NASA and JAXA, are also foreseeing to deploy similar infrastructure, which will all be interoperable according to the LunaNet Specification. One of the critical phases in both human and robotic lunar exploration is the landing of spacecrafts on the Moon’s surface. This operation is complex and challenging, as demonstrated by recent crashes like the Luna25 lander from the Russian Space Agency or the Intuitive Machine private lander. Reliable positioning capabilities during descent are among the various services offered by dedicated lunar navigation systems and shall enable safe and reliable landing to a 90 metres 3-sigma landing accuracy from a target point, as defined by the Global Exploration Roadmap Critical Technology Needs. Faulty landings can be due to several causes. This paper examines the achievable positioning accuracy for a lander targeting the Moon’s South Pole using satellite-based navigation services like Moonlight and how the impact of faulty sensors (such as a faulty IMU) can be mitigated using Moonlight LCNS.