Orbit Analysis for Tiangong-2 Space Lab Under Different Perturbation Forces

Abstract

Tiangong-2 is a space laboratory of China, which carries out various the Earth observations and space experiments. Controlling of the Tiangong-2 and completing these experiments rely on high precision orbit information. Hence, study on perturbed motion, which can be switched to analyze perturbation forces is the basis and core tasks. Firstly, in order to analyze the influence to the orbit by the perturb forces, initial orbit state is obtained by two line elements. Furthermore, several integral orbits are achieved under different perturb forces using numerical integration method, including the Earth potential perturbation, tides, three body perturbation, atmospheric drag perturbation, the solar radiation pressure and the Earth albedo. The experimental result shows that the atmospheric drag perturbation is one of the key factors to constraint the orbit accuracy and much more complex, due to the fact that Tiangong-2 is a low Earth orbit spacecraft. Moreover, atmospheric drag perturbation is discussed in details for comparing different upper atmosphere density models. And its orbit affect level is concluded, which is benefit for precise orbit determination.