The Design and Analysis of a Lunar Navigation SmallSat for Southern Hemisphere Moon Navigation

Being Earth's only natural satellite, the moon is crucial for human space exploration and serves as a vital base for additional deep space endeavors. Cislunar space represents an extensive domain for expanding human habitation beyond terrestrial land and oceans. The pursuit, building, and advancement of cislunar space have escalated the need for cislunar navigational capabilities. Currently, GNSS navigation technology has been well-established for Earth and near-Earth regions and is now being extended to encompass the cislunar realm. Concurrently, the progress in small satellite technology presents fresh opportunities for the rapid and effective implementation of small satellite navigation networks. Addressing cislunar navigation needs, this document suggests creating a navigation system in small space using BDS (BeiDou Navigation Satellite System) time-transfer technology on a compact satellite platform in earth-moon libration point orbits. A variety of orbital paths, such as DRO (Distant Retrograde Orbit) and NRHO (Near Rectilinear Halo Orbit), are employed to form a navigational constellation under the framework of a small satellite platform operating in earth-moon libration point orbits; BDS timing is utilized to compensate for limited payload capacity on small satellites as well as limitations in star clock accuracy. This paper presents the design architecture analysis of such a cislunar space small-satellite navigation system employing BDS time-transfer technology while systematically studying various multi-orbital characteristics adopted by this system along with its corresponding navigational features. Furthermore, observability analysis is conducted on these navigational constellations while evaluating their performance through relevant accuracy indicators across several constellation design scenarios. This paper confirms the practicality and initial efficacy of the cislunar space small satellite navigation system, employing BDS for time-transfer, serving as an essential guide for BDS and GNSS in providing navigational services in cislunar space. An innovative idea and approach for navigating lunar space and the southern hemisphere's moon is suggested.