Optimal servicing of geostationary satellites considering earth's triaxiality and lunisolar effects

The objective of this paper is to find the minimum-fuel transfer needed for servicing client geostationary satellites while considering perturbations that have been neglected in previous studies. The effect of Earth's triaxiality on the semimajor axis and longitude is derived by the method of averaging and used for designing a two-impulse planar phasing maneuver. The phasing maneuver is then extended to a three-impulse planar maneuver for matching the eccentricity. The inclination variation due to lunisolar perturbations is modeled to determine the maneuver needed for eliminating the normal direction excursion. Then, an optimal servicing model is built with Earth's triaxiality and lunisolar perturbations included and applied for servicing a sparsely distributed geostationary constellation. The results show that the duration of each rendezvous of the optimized solution is mainly determined by third-body effects. The proposed maneuver strategy with a tesseral-term correction can achieve relatively high accuracy in longduration orbital transfers under the effects of Earth's actual gravitational field, lunisolar attraction, and solar radiation pressure.