Abstract: A reachable zone generation method based on the dynamic neighborhood search is developed for landing on irregularly shaped asteroids. Firstly, the reachable zone is formulated, and a centroid distance mapping function is designed to constrain the terminal position of a trajectory with an unfixed landing point. On this basis, the reachable zone generation problem is decomposed into three sub problems: the reference point calculating, the starting point calculating, and the boundary points searching. The reference and the starting points are solved by a trajectory optimization for minimum fuel and maximum distance, respectively. The boundary points are calculated using a guided dynamic neighborhood search method, and in each search cycle, the minimum fuel is optimized with a fixed landing point. Finally, the proposed method is verified using the 433 Eros model. The results indicate that the method is effective in generating a reachable zone on an irregular surface, efficient in searching the boundary points, and applicable to various initial positions and fuel consumptions.

Key words: Asteroid landing, Reachable zone, Trajectory optimization, Neighborhood search