Towards Cis-Lunar Navigation: Design and Analysis of a SmallSat System with Time-Transfer from BDS

The Moon, as the only natural satellite of the Earth, is a crucial destination for human space exploration and serves as a foundation for deeper space exploration. Cis-lunar space offers vast opportunities for human expansion beyond the Earth’s land and ocean. The exploration, construction, and development of cis-lunar space demand enhanced cis-lunar space navigation. While GNSS navigation technology for the Earth and near-Earth space is well-established, extending it to cis-lunar space is the current stage. Small satellite technology development provides new ideas for efficient and rapid deployment of small satellite navigation constellations. To meet the cis-lunar space navigation demands, we propose a small space-based navigation system using BDS for time-transfer, based on Earth-Moon libration points orbits and small satellite platform.

In this paper, we systematically study the multi-type orbital and navigation characteristics adopted, and design and analyze the architecture of the cis-lunar space small satellite navigation system using BDS timing. The proposed navigation constellation using multiple types of orbits, including DRO, NRHO, etc., is timed through BDS to compensate for the limited load of small satellites and the limited accuracy of the star clock. We analyze the observability of navigation constellations and evaluate the navigation performance of several constellation design cases using corresponding accuracy indicators. Our results verify the feasibility and preliminary performance of the proposed cis-lunar space small satellite navigation system using BDS as time-transfer, and provide a reference for BDS and GNSS to provide navigation services to cis-lunar space. We propose a new idea and method for cis-lunar space navigation that combines BDS navigation technology and small satellite platform, and which holds great promise for future space exploration.