Control strategy study of colocated GEO satellites based-on eccentricity vector separation

As the number of geostationary earth orbit (GEO) satellites continues to increase, it is becoming more common for two or more GEO satellites to colocate in the same geographical longitude over the equator. As a consequence, the risk of collision is increased significantly. So various control methods for GEO satellites to colocate are applied in order to ensure the safety of these satellites. This paper mainly focuses on the control strategy study of two colocated GEO satellites based on eccentricity vector separation. In this study, the difference between eccentricity vectors of two colocated GEO satellites is taken into account in order to guarantee that the maximum distance is maintained between two satellites in the same orbital plane. In order to obtain the optimal control strategy, three main control methods concerning eccentricity vector separation are discussed here. In the method of absolute eccentricity vector separation, the eccentricity of one GEO satellite is much larger than that of the other GEO satellite, and the movement region for two satellites does not overlap in the space. The second one is the relative eccentricity vector separation method which means the difference between two eccentricity vectors is very distinct in both the vector direction and vector size, thus one of the two colocated GEO satellites circles around the other. The third method is one kind of joint control method which combines the eccentricity separation and the inclination separation. At the end of this paper, some dynamics simulation results are given to prove the feasibility of these methods.