Improvement study of B-plane method for trajectory correction maneuver of lunar exploration

Abstract

In lunar mission, trajectory correction maneuver (TCM) dominates success of mission. B-Plane targeting method is widely used in TCM for external celestial sphere of interference (SOI) incoming mission. However, it is clear that B-Plane method has two problems. The first problem is divergence of numerical partial differentiation of B-vector sensitivity matrix with size of perturbation velocity. The second is that trajectory correction by time of closest arrival (TCA) cannot guarantee precise perilune attitude. Therefore, two improvement studies for B-Plane method are suggested in this paper. The first improvement is analytical solution of sensitivity matrix of B-vector. From this analytical solution, it is possible to execute trajectory correction maneuver identical to numerical partial differentiation method without any danger of divergence. The second improvement is perilune altitude correction by eccentricity. By eccentricity TCM, it is possible to correct perilune more precisely than previous method.