Optimum Orbit Transfer And Rendezvous Of Spacecraft

This paper investigates problems of optimum orbit transfer and rendezvous. According to optimal control theory and the Pontryagin maximum principle, kinetic variables and kinematic variables are selected as state variables respectively.Kinetic variables are displacement and velocity vectors. Firstly, the optimal control equations are founded in cartesian coordinate system. The analytic solutions of impulse orbit are analyzed detailedly and the optimal control solutions of coplanar impulse transfer orbit are determined. Secondly, the optimal control equations of limited power transfer and its numerical solution are developed. Finally, the optimal control equations in polar co-ordinates and its numerical solution are introduced.Kinematic variables are orbit elements of spacecraft. The analytic solutions are determined for optimum low-thrust power transfer and rendezvous between arbitrary neighboring orbits in strong gravity fields. After applying mean element method, the analytic solutions are determined for optimum low-thrust power transfer transfer and rendezvous between arbitrary neighboring orbits in considering the Earth's oblateness. The changes of optimal trajectory caused by Earth's oblateness are computed.Several conclusions are summarized from this paper: the optimal control equations based on kinetic variables can expediently develop the coplanar analytic solutions which have clear kinetic meaning; the optimal control equations based on kinematic variables can get its analytic solution of space orbit transfer and can get the analytic solution when considering the Earth's oblateness. In actual application, we can use the optimal control solutions of this paper according to different simplification.