1·When solving required velocity, it real-timely thinks about influence of oblateness of the earth and gives the process of solving required velocity by midcourse trajectory method.
求解需要速度时，实时地考虑了地球扁率的影响，并给出了利用中间轨道法求解需要速度的过程。
2·Determining the oblateness is extremely difficult.
测量扁率是极为困难的。
3·Simple form unretarted orbit of space vehicles under the first order perturbation of the oblateness of the earth is obtained in this paper.
本文求得了空间飞行器在地球扁率摄动作用下简单形式的一阶解。