Orbit Raising and De-Orbit for Coplanar Satellite Constellations with Low-Thrust Propulsion

This paper deals with the planar transfer problem (i.e. orbit raising and deorbiting phases) for low Earth orbit coplanar satellites constellation. The objectives are to minimize the total time of transfer and to maximize the miss distance during these phases so as to minimize the collision hazard. A Blended Error- Correction (BEC) steering law, consisting of tangential thrust and inertial thrust based on the offset in mean orbital parameters, is developed to design the transfer trajectory for a single satellite. The semi-analytical technique is used to evaluate the variation in orbital parameters over one orbit revolution to reduce the computation load. The numerical results show that the BEC steering law is able to identify near time-optimal solutions and the semi-analytical results have good accuracy. For multiple satellites transfer, the orbit transfer trajectory designed for a single satellite is used as a baseline for a global multi-satellite analysis of the miss distance among pair satellites during the orbit raising and de-orbiting phases. Considering limits on the transfer starting time for de-orbit mission, multi-objective optimization is used to find out the optimal transfer starting time for each satellite.