Phasing Mission Optimization Approaches And Relative Orbit Propagation Algorithms For Autonomous Rendezvous

Driven by the missions such as space station rapid supplies, space emergency rescues, and sample return from other celestial bodies, the rendezvous and docking technology is advancing to near- Earth short autonomous and deep space autonomous directions. This dissertation studies the new mission design problems arose in autonomous rendezvous mission, including the phasing mission optimization and the high-precision relative orbit propagation. The main achievements are summarized as follows.The phasing strategy and some key parameters for near-Earth short rendezvous mission are designed. 1) Based on the China’s two-day profile of near-Earth rendezvous and docking mission, a flight program for five-orbits short-rendezvous phasing mission and a n optimization model based on modified special-point maneuvers are proposed; 2) The required orbital determination precision to meet the terminal control accuracy and the optimal phase range corresponding to a given duration are presented; 3) The influences of the target spacecraft’s orbital altitude, the chaser’s orbit insert precision, and the chaser’s apogee height on the optimal phase range and total velocity increment are analyzed.A two-level optimization approach for long-duration, large non-coplanar rendezvous phasing mission is proposed. 1) A relative dynamics equation-set considering the J2 perturbation and the coupling effects between maneuver components and orbital element differences is derived, which is employed to efficiently obtain a feasible solution for a long-duration, large non-coplanar rendezvous problem; 2) A two- level optimization approach is built for the long-duration, large non-coplanar rendezvous phasing mission using combined maneuvers, which is solved using a hybrid method combining the linear search, a mixed-coded genetic algorithm and the sequential quadratic programming; 4) The efficiency and robustness of the proposed two- level optimization model and algorithms are testified by solving the typical Mars orbital long-duration, large non-coplanar rendezvous-phasing problem, besides our approach obtain better solutions than previously published results for all the test cases with 3~6 impulses maneuver schemes, by reducing at least 20% in the total velocity increment.Two high-precision relative orbit propagation algorithms using least-squares method are proposed. 1) Through analyzing the propagation accuracies of four typical relative motion equations, it is found that the accuracy of these relative motion equations varies greatly with the initial argument of latitude of the reference spacecraft, which was seldom mentioned in previous studies; 2) Two novel practical relative orbit propagation algorithms using least squares method based on the C lohessy-Wiltshire equations and their second-order versions are proposed; 3) The numerical results based on one practical mission’s orbital data show that the proposed algorithms clearly have a better long-term accuracy than those four relative motion equations, and their accuracy are almost unaffected by the argument of the latitude of a reference satel ite.The proposed long-duration, large non-coplanar rendezvous phasing optimization approach and the high-precision relative orbit propagation algorithms using least squares method are theoretically of significance. The presented maneuver plan and some typical parameters for near-Earth short rendezvous mission can provide valuable references for engineering design.