Positioning of a Lunar Lander Using a Dedicated Lunar Communication and Navigation System Assuming Realistic ODTS Performances

With the renewed interest in the Moon, manifested by the growing number of planned missions for the past decade, space agencies are investing in reliable and dedicated lunar communication and navigation systems and services, such as the Moonlight programme of the European Space Agency (ESA), to provide support to all types of lunar users (i.e., surface users, landers and orbiters).In the context of lunar human and robotic exploration, one of the critical phases will be the landing of spacecraft on lunar soil.This type of operation is far from trivial, as shown by the recent crashes such as the one of the Luna25 lander from the Russian Space Agency.A reliable method to position a lander during its descent could be provided by a dedicated lunar navigation system.This paper will focus on what the achievable positioning accuracy is for a lander landing on the Moon's South Pole using dedicated satellite-based navigation services such as Moonlight.It will be shown that using the LCNS constellation and the altimeter can achieve a sub 50 m accuracy with a 99% confidence interval.