A Novel Navigation Message for Future LCNS Satellites

With the renewed interest in the Moon, several countries are launching projects to explore the Moon (at both institutional and private level). As part of the Moonlight Programme, the European Space Agency (ESA) is developing Lunar Communication and Navigation Services (LCNS) with its industrial partners. The Moon orbits, specifically the Elliptical Lunar Frozen Orbits (ELFO), are quite different compared to the GNSS orbits. This work presents a novel orbit model for the LCNS that can support different ELFOs and other orbits. The performance of the new model is measured in terms of accuracy and the number of bits (required to broadcast the information) against other available models. Such a model could be used to broadcast the ephemeris of the LCNS satellites within the navigation message of the LunaNet Augmented Forward Signal (AFS).