Initial costates for low-thrust minimum-time station change of geostationary satellites

A minimum-time station change of geostationary satellites is formulated using the indirect method. An analytical method is presented for the evaluation of the final time, as well as the initial costates of semimajor axis, longitude, and mass. The analytical method does not require the properties of the initial costates, which were obtained in previous studies by establishing a relationship between the initial costates and the transfer time. The indirect optimization method demonstrates rapid convergence when employing the initial costates evaluated by the presented method. revolutions be close to an even integer. A low-thrust minimum time station change with perturbations included requires no significant change in flight time relative to that without perturbations. Under the effect of the most significant perturbations acting on geostationary Earth orbits, the low-thrust station change maneuver achieves similar accuracy as an impulsive maneuver.