从月球逃逸探测小行星的发射机会搜索

从月球逃逸探测小行星的发射机会搜索因需考虑日、地、月引力的影响而使问题变得复杂。针对该多体系统的发射机会搜索问题，提出了一种分层渐近的搜索方法。该方法首先通过分析地月系质心与小行星的几何关系，搜索从地月系质心到小行星的发射机会，进而以地月运动为研究对象，推导出了从月球轨道切向逃逸机会的判别条件，并基于此判别条件及等高线图法对逃逸机会进行了搜索。同时，为提高所得发射机会在多体模型下的轨道修正收敛性，给出了基于月心逃逸轨道参数为终端约束的日-地与日-地-月动力学模型的轨道渐近修正方法。最后，以近地小行星(3908)Nyx和(190491)2000 FJ20为例，搜索其从月球逃逸的发射机会，仿真计算表明了该方法的有效性。

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.