Preliminary design of transfer trajectories for asteroid exploration missions

This paper presents a segment-by-segment approach for designing transfer trajectories from the low-Earth parking orbit to a target orbit around an asteroid. With three-dimensional high-fidelity model incorporating n-body dynamics and planetary ephemeris, we design an optimal Earth-asteroid transfer trajectory that minimizes initial and final velocity increments. To alleviate numerical sensitivity which is often caused by stringently satisfying the departure and arrival conditions, the design process is divided into several segments. Then, parametric studies based on numerical optimizations are performed by changing orbital elements of departure orbit. In this way, the tendency/correlation of design variables/parameters is analyzed and their optimum values are determined.