NUMERICAL OPTIMIZATION STUDY OF AEROASSISTED ORBITAL TRANSFER

A direct multiple shooting method has been applied to the optimization of an aeroassisted orbital transfer. The objective has been to provide optimal trajectories for a vehicle with a high lift-over-drag ratio that minimizes the energy loss during the atmospheric part of an aeroglide maneuver subject to limits on heating rate. In addition, thrusting segments have been inserted within the atmospheric part of the trajectory, and both aeroglide and aerocruise trajectories have been evaluated. Here, the objective has been to maximize the achievable inclination change subject to limits on heating rate, total heat load, and lift coefe cient. The respective parameter optimization procedures have been set up as multiphase optimization problems. All guidance-related parameters along the trajectory, together with the deorbiting, boost, and circularizing impulses, have been optimized.