Thrust Estimation Of Electric Propulsion Based On Measured Data And Orbital Maintenance Of Fly-around

The paper is based on the on-orbit experimental study conducted by aninstitute of China Aerospace Science and Technology Corporation (CASC). Inthe setting of fly-around orbits of patrol satellites in space station, this paperaims at undertaking a theoretical study regarding it as well as its design andplanning. The followings are concerned with the main research contents.Firstly, to get the thrust force from the application of two kinds of electricalthrusters, feasible ways are utilized including data analysis and screening,electrical formulas, comparison and analysis with technology index value.However, in the method of the application of electronics, as some parameters aredrawn from the ground experimental data and the conditions of groundexperiment differ from that of space experiment, the thrust force value acquiredis not precise enough. In this regard, with the adoption of orbital data measuredby on-orbit GPS and J2item perturbation, the paper will, through spacecoordinates transforming relation and orbital dynamics equations, make thecalculation of thrust force value in an inverse way in order to get more precisevalue. The outcome of the calculation will also be employed as reference data forfly-around mission of patrol satellites in the following chapter.Given that the earth is not influenced by its shape, the perturbation relativedynamics equation between patrol satellites and space station is established. Thefly-around orbit of patrol satellite has been designed according to the relativedynamics equation calculated after linear programming. Besides, the relativedynamics equation under the issue of two-body is based on the method of C-Wequation. In this paper, the analytical solution is gained through C-W equationunder the condition of natural fly-around, namely when all interference forcetogether from external environment offsets the thrust force from thrusters. Inaddition, the results of the following three researches will also be obtained fromthe calculation: the configuration of fly-around orbit, the relative dynamics equation under the application of J2item perturbation and the impacts of J2itemperturbation has on fly-around orbit of patrol satellites. All these mentioned willlay the foundation for the design and simulation of control rate maintenance offly-around orbit in the following chapter.In practice, the original configuration of fly-around orbits must be kept out ofconsidering J2item perturbation effects. The paper will then take the influencesinto account, and under which six change rates of orbit elements are deduced.When designing fly-around orbit, analytical solution obtained from linearprogramming are presented in advance. After the comparison between relativedynamics equation in the actual situation and the one based on Hill equation, thedifferences of them will be calculated, which then figure out the control methodbased on continuous PD feedback rates from low-thrust design. Ultimately, theconclusion of the paper will be about whether electrical thrusters can meet therequirements of mission.