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 spacecrafts on the lunar soil. This type of operation is far from trivial, as it was 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 is the achievable positioning accuracy for a lander landing on
the Moon’s South Pole using of dedicated satellite-based navigation services such as Moonlight. It
will be shown that using the LCNS constellation and the altimeter can achieve a sub 50m accuracy
with a 99% percentile confidence interval.