Trajectory design and control of in-plane fast controlled flyaround

The flying around motion of spacecraft is a periodic visual motion that a chaser spacecraft encircles a target spacecraft. There are two kinds of flyaround: natural flyaround and fast controlled flyaround. Flying around satellite has more important applications in on-orbit satellite servicing and on-orbit spacecraft support, supporting the extra-vehicular activity (EVA) of astronaut, spacecraft formation flying, spacecraft rendezvous and docking, etc. This paper is concerned with the trajectory design and guidance problems of a flying around satellite to accomplish in-plane fast controlled flyaround. At first, the feasibility and the process of the fast controlled flyaround are analyzed. Then, a mathematical model, which is applicable to the situation that target spacecraft flies in a circular orbit, used to design and control the in-plane fast controlled flyaround trajectory is presented, which includes in-plane fast flyaround, entering into and exit flyaround. The multi-impulse control method and equal angle equal time control mode is used to fulfill the control of fast controlled flyaround trajectory. Finally, taking into account perturbations and navigation errors which can cause the trajectory unstable and mission impossible some simulation works are carried out. The results indicate the fast flying around mathematical model and the trajectory control method can accomplish the in-plane fast controlled flyaround.