这个课题设计从地球的近地轨道起飞到达谷神星预定轨道并且着陆在其表面上的一种数值方法。基于有限时间的航行纠正点火而非瞬时推力数值计算和Matlab仿真。最后可以看到空间飞行器从地球的影响球飞到谷神星的影响球的飞行轨迹。-This project explores the mathematical methods and results of designing a mission to land a spacecraft on the asteroid Ceres by beginning in an earth-centered LEO orbit and ending in an orbit prepared to land on the surface of the asteroid. Rather than assume instantaneous velocity changes, course-correcting burns of finite time are considered and analyzed using numerical methods and Matlab computation. The behavior of the spacecraft is observed inside the Earth s sphere of influence, in interplanetary space, and inside Ceres　sphere of influence.