CURVILINEAR SURFACE-BASED GRAVITY MODEL FOR EVOLUTIONARY TRAJECTORY OPTIMIZATION AROUND BENNU

Missions to small bodies often require a mapping phase during which low altitude operations are required. These low altitude trajectories need to fulfill competing objectives such as: camera surface coverage, camera viewing angle, propellant usage, and safety from impact. The high-dimensional optimization space lends itself to population-based optimization techniques. These methods however, require a large number of trajectories to be integrated, and thus require an accurate gravity model that is quick to evaluate. In the present work, a quadrature-based surface gravity model is developed for use in a differential evolution trajectory optimization routine. Recommendations are made regarding the required number of quadrature points and the order of the quadrature for the problem at hand.