Orbit Prediction And Short-range Rendezvous Phase Coordinated Control Of Non-cooperative Target

The number of on-orbit spacecraft grows rapidly as the expanding of human exploration into the space.However,once the spacecraft retire,they turn to active debris which threaten the active spacecraft on orbit.In view of this problem,this paper mainly does the following work.First,this paper studies the orbit prediction of non-cooperative target in space.Applying Grace and Swiss Cube,the uncertainty of non-cooperative target orbit determination is studied based on TLE.Considering the accuracy of orbit model and calculation efficiency of orbit prediction,the model used to study Grace and Swiss Cube is determined by analyzing different models with different perturbations and comparing the difference between perturbation models and HPOP model in different time spans.Considering the GPS of the non-cooperative target can’t be obtained,a new method named arc-overlap is used to analyze the inaccuracy of predicted orbit.Then,according to the statistical error characteristics of predicted orbit,the noncooperative target is regarded to sit in a spatial ellipsoid with a giving probability density distribution function.By studying the observation capability of tracking satellite in same orbit,high orbit and low orbit,the optimized initial position of tracking satellite relative to the target can be obtained by using the Monte Carlo Method.Finally,in the short-range rendezvous phase,considering the tumbling motion of target may threaten the tracking satellite which is ready to have rigid connection with the target,such as harpoon or robot arm,the tracking satellite needs to be controlled so to attitude coordinated with target.The energy consumed and the dimension of reaction wheel in this stage is calculated,which provides reference for the future research.