Optimization and deployment method of cislunar communication and navigation constellation based on libration point orbits

The Earth–Moon libration point orbit (LPO) offers unique advantages in terms of location and dynamical characteristics, providing new opportunities for designing communication and navigation constellations. However, LPOs cannot be described by Keplerian elements and require significant computational resources for initial value searches, limiting their optimization potential. This paper proposes a two-step optimization algorithm based on a two-layer initial value library. The first layer represents orbit families, while the second layer contains orbits with varying amplitudes within each family. The first step of the algorithm quickly filters orbit families, and the second step selects the orbits that form the constellation, significantly reducing both the optimization scope and the number of parameters. We introduce a novel grid-based division of key cislunar regions and expand the constellation service area using a three-phase construction strategy. To evaluate the optimized constellation’s navigation capabilities, we test its performance with typical orbits, including Earth–Moon transfer orbit (EMTO), elliptical lunar orbits (ELO), and geosynchronous orbit (GEO). Experimental results show that a single near rectilinear halo orbit (NRHO) satellite provides single coverage of the Earth–Moon transfer critical region at sampling times, with an orbit determination (OD) accuracy of 475.7 m for the EMTO. Seven satellites, positioned on the L1, L2, L4, L5, and NRHO orbits, achieve quadruple coverage for both the Earth–Moon transfer and near-Moon regions, with OD accuracies of 25.7 and 17.3 m for the EMTO and ELO, respectively. In the third phase, adding two L3 LPO satellites forms a nine-satellite constellation, extending coverage across the entire cislunar space, achieving OD accuracies of 15.1, 13.4, and 2.2 m for the EMTO, ELO, and GEO, respectively. This study provides valuable insights for the future design and deployment of cislunar communication and navigation constellations.