When the observation station and the satellite or the spaceship are coplanar, the earth can be approximated into an uniform sphere. By applying the sine rule of plane geometry, the orbit arc length can be calculated which each observation station can measure. Numbers of observation stations should at least be established can be calculated by using the ratio method. When the earth’s self-rotation is taken into account, we can calculate the fewest numbers of observation stations by calculating the area of spherical surface that each station can observe and combining the division of regular hexagon of a football. In the end, the article analyzes the related material of ShenZhou V and the period of time of each station.