Lunar Communication and Navigation Services: The Lander Navigation Use Case

Filippo Rodriguez, Riccardo Petix, Gabriele Lambiase, Marco Sabatini, Giovanni Palmerini, Maurizio Gasbarra, Laura De Leo, Gabriele Paggi, Cosimo Stallo, Richard Dennis Swinden, Floor Thomas Melman, Monica Gotta

Abstract:	The renewed push for lunar exploration is accelerating, leading to an increasing number of missions orbiting and landing on the Moon, with many more expected in the coming years. However, these operations are extremely complex and risky due to significant navigation challenges. Current technologies, primarily based on visual imaging, struggle with extreme light contrasts, pitch-dark regions, and limited map accuracy, making precision landings particularly hazardous. Overcoming these challenges is critical to ensuring the safety and success of future lunar missions and long-term human presence. The Lunar Communications and Navigation Services (LCNS) project, led by Telespazio and part of ESA’s Moonlight programme, aims to provide advanced communication and navigation services to facilitate difficult operations and overcome the challenges of such missions, ensuring greater accuracy, reliability, and safety for future lunar exploration. The LCNS one way ranging service (OWR) is particularly exploited to provide a PVT solution for the landing use case. This service is very similar to the well known terrestrial GNSS and implements the LunaNet standard. In particular it is compatible with the AFS signal specifications, described in the LNIS (LunaNet Interoperability Specifications) Annex dedicated to AFS signal description, LSIS (LunaNet Signal In Space). Since the LCNS constellation is composed of 4 satellites, in order to cover the entire landing mission final descent phase, the use of LCNS as navigation system should be complemented by additional sensors and techniques. Among the others, altimeter and IMU are exploited as additional sources of information: the altimeter is used to better estimate the height over the surface, whereas the IMU is used for acceleration and orientation measurement. The developed navigation filter follows the usual steps of the Extended Kalman filter. It merges the noisy measurements produced by simulated sensors with the propagated state, obtained implementing a nonlinear orbital propagator. Using a realistic landing profile, Montecarlo simulations were carried out to analyze the performance of the position and timing solution. The results show full compliance with the LCNS position and velocity requirements related to the landing use case, as well as important considerations concerning the impact of the constellation geometry and the role of IMU and altimeter. The LCNS constellation coverage is optimized such that it is clear in some time windows the LCNS standalone PVT is possible even without any sensor fusion still fully matching the promised LCNS performance.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	623 - 643
Cite this article:	Rodriguez, Filippo, Petix, Riccardo, Lambiase, Gabriele, Sabatini, Marco, Palmerini, Giovanni, Gasbarra, Maurizio, De Leo, Laura, Paggi, Gabriele, Stallo, Cosimo, Swinden, Richard Dennis, Melman, Floor Thomas, Gotta, Monica, "Lunar Communication and Navigation Services: The Lander Navigation Use Case," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 623-643. https://doi.org/10.33012/2025.20310
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