Searching launch opportunity of asteroid exploration from moon departure

Searching launch opportunity of asteroid exploration escaped from Moon needs to take into account the gravity of Earth, Sun and Moon, A step by step and asymptotic method is proposed to search the launch opportunity for the multi-body dynamics model. In this method, the launch opportunity of transfer from Earth-Moon system to asteroid is searched in two-body dynamics model. The Earth-Moon motion is investigated to deduce the criterion of opportunities escaped from lunar orbit's tangent, and then the criterion and the contour map method are used to search launch opportunities. In order to improve the convergence of launch opportunity correction in multi-body dynamics model, an asymptotic correction strategy is adopted to correct the launch opportunity in Sun-Earth system and Sun-Earth-Moon system based on lunar escape orbit parameters as terminal constraints. The effectiveness of the proposed approach is demonstrated through the launch opportunities search of asteroids (3908) Nyx and (190491) 2000 FJ20 flyby missions escaped from Moon.