Guidance and control for satellite proximity operations

Purpose - In this paper, the development of relative guidance and control algorithms for proximity operations to satellite in elliptical orbit are presented. The paper aims to discuss these issues. Design/methodology/approach - The process of autonomous proximity is divided into three phases: proximity manoeuvre, flyaround manoeuvre, and hovering manoeuvre. The characteristics of the three phases are analyzed. Different guidance algorithms are based on using the analytical closed-form solution of the Tschauner-Hempel (TH) equations that is completely explicit in time. Lastly, the linear quadratic regulators control algorithm based on the linearized TH equations is developed to minimize the initial state errors in the fast phase. Findings - This paper defines three phases in the satellite proximity operations and develops the guidance and control algorithms. Then, the relative guidance and control algorithms are illustrated through different numerical examples. And the results demonstrate the effectiveness and simplicity of using a TH model in autonomous proximity. Practical implications - The findings indicate that a TH model is clearly effective at estimating the relative position and velocity and controlling the relative trajectory. In addition, this model is not restricted to a circular orbit, but it can be used as well for an elliptical orbit. Furthermore, by using this model, simple guidance and control algorithms are developed to approach, flyaround and hover from a target satellite. Originality/value - Based on the guidance algorithms, the manoeuvre-flight period can be set in accordance with the mission requirement. Flyaround with different types of trajectory and a feedback control scheme to achieve stable hovering state are studied. Consequently, this proposed guidance algorithms can effectively implement guidance and control for satellite proximity operations.