Abstract:

Taking both minimization of the fuel consumption and maximization of the fliedover asteroids as the performance index, the flight trajectory for multi-objective in space exploration by low-thrust is globally optimized by a combined algorithm of trajectory optimization. The strategy of trajectory design consists of global optimization and local optimization. As a concept design, the global optimization is to approximately determine exploration sequences and node times after simplifying spacecraft trajectory generated by low-thrust. The launch window of each flight trajectory is comprehensively searched in a big search space by the static parameters optimization algorithm, namely the exhaustive method. Each part of approximate solutions of optimal trajectories and the control law are calculated accordingly. Then the local optimization is used by the conjugate gradient algorithm to solve twopoint boundary value problems of each suboptimal trajectory. Meanwhile, each part of the optimal trajectory and optimal control law are calculated based on the approximate solutions, which respectively make up global optimal trajectory and global optimal control law.