行星际飞行器运动理论
Theory of the motion of interplanetary vehicle
你们城市有那种地球站吗？就是作为中继向人造卫星和星际飞行器发送的或中继来自这些地方的无线电信号的地面基地？
Is there an earth station , a base for relaying radio signals to and from artifical satellites and interplanetary sapcecraft , in your city ?
星际飞行器