A comparison of accuracy and efficiency of three control strategy design methods for low energy moon return mission

In this paper a comparison is made between three thrust steering strategy design methods for the low energy moon return mission. The dynamic equations are given under the elliptical four body problem and the virtual satellite method applied to establish the control model. Because of the narrow launch window and weak stability of the low energy return orbit, the spacecraft must inject into the target orbit with a high accuracy while it´s necessary to finish the optimization within a short time. So the efficiency and accuracy of the three methods, the changing thrust angle iteration method, the maximum principle optimization method and the Gauss pseudo spectral method are analyzed in a simulation example. From the result, it´s found that, though the changing thrust angle iteration method cannot give an accurate control strategy but the high efficiency of the algorithm can provide a preferable original value for the other methods to decreases the amount of computation in solving the accurate optimal control strategy.