Orbit Design And Launch Window Selection For Lunar Lander

It is a key step to land on lunar surface safely with the lander for our lunar exploration. The orbit design of the lunar lander is very important. In this thesis, the problems of orbit design and launch windows were studied. The main results and conclusions are as follows:a. The dynamics of the lunar lander orbit was discussed. The time systems and the coordination systems that refered to the design process of translunar-trajectory were introduced. The simplified model based on the double two-body hypotheses was given. And the whole dynamics model of the translunar-trajectory was established considering different forms of contributing factor comprehensively.b. The problem of selecting the launch window for the lunar probe was studied. Taking the light constraint into account, the month-launch-window was given by limiting the illumination of the landing point and the perilune point. According to the limitation of two ground TTC stations, the day-launch-window was given. Considered the orbit kinematics constraints comprehensively, including which on lunar satellite orbit, lunar soft landing orbit, earth parking orbit and translunar-trajectory, the whole orbit window was determined finally. The lunar lander window of the second half year in 2013 was searched, and the entire windows that meet the mission requirement were obtained.c. The design and optimization of the lunar lander orbit was developed. Two kinds of appropriate optimization searching algorithm for the lunar orbit design were introduced systematically. One was based on the evolution strategy, the other one made use of the B-plane differential corrector. Based on the two kinds of orbit design method, the high precision orbit design software was developed. Combined with the found mission window, all the orbit of the lunar probe which meet the mission requirement during the second half year in 2013 were gained, and the characteristics of these orbits were analyzed. At last the problem and disciplinarian in the design process were summarized.In conclusion, this thesis grounded on the lunar exploration investigation of the lunar lander mission, the selection of launch and the model and method of the orbit design were summarized completely. The design and simulation software were developed. The whole work of window selection and orbit design were processed according to the practical mission requirements and constraints, and the window and orbit that meet the requirements were got, which has the important reference value to the orbit selection of the lunar exploration mission.