TRANS-LUNAR TRAJECTORY DESIGN FOR LUNAR PROBE ASSEMBLED IN LEO

摘要

It is important to research the lunar exploration based on the Low Earth Orbit (LEO) transportation node assembly. Within the existing launch power, more payloads can be carried to the Low Lunar Orbit (LLO) or the surface of the moon in this mode. More complex mission for lunar exploration or manned lunar landing can be performed. However, after assembly, the parking orbit near the earth for the lunar probe leaving is fixed. If orbit maneuver, especially out-of-plane maneuver is implemented in LEO for the mission of cislunar transfer, more fuel would be consumed. To reduce the consumption of propellant, it is important to design the trans-lunar trajectory of lunar probe leaving from the fixed parking orbit near the earth. In this paper, considering the kinematic law of the moon, an integrated mathematical model is established, and the constraint conditions are given according to practical situations in engineering. Then the main problem for trans-lunar trajectory design is solving the orbit dynamics equation in some constraint conditions. As it is difficult to solve it directly, optimization method is used in this paper. Appropriate object function and constraint conditions are chosen, and the equation is solved by using genetic algorithm and SQP method. The parameters of trans-lunar trajectory are calculated using numerical method. At last, using STK software, a method for revision of the results in primary design is given, and the high precision trans-Lunar trajectory is gained.