借助光压将探测器推向月球

若采用圆型限制性三体问题模型，从近地停泊轨道上发射一个月球探测器，其最小初始速度必须使相应的Jacobi常数C小于某一临界值C2。但这仅仅是探测器可能飞向月球的必要条件，而且这样飞向月球耗时过长。若采用Hohmann转移轨道，则需要获得较大的变轨冲量，能量消耗较大。如果需要仔细探测地月空间环境，而又不必很快地飞往月球，那么采用较大的太阳帆板，并使其法向有一特殊指向，可借助太阳光压加速引导探测器在不长的时间内飞向月球。利用相应的分析和计算，证实上述考虑是有效的，而且若使太阳帆板截面积大到一定程度（如果技术上能实现），则无需任何动力，也可借助光压将探测器推向月球，就像一条太空帆船（简称太空帆）。

TO GUIDE A PROBE TO THEMOON WITH LIGHT PRESSURE

In the dynamical model of the circular restricted three-body problem and for launching a lunar probe from parking orbit, the minimum initial velocity should satisfy the condition that the Jacobian constant C is smaller than C2 (in the Earth-Moon system, C2=3. 20034491). Then the probe may be accelerated to a speed of Vv ＞ 10. 8746 km/s at perigee (some 200 km high). However, this is only the necessary condition for the probe to fly to the moon and the voyage time is too long. If a Hohmann transfer orbit is adopted, a more impulse for the orbit transfer will be required, and in a sense more power will be consumed. If it is needed to carefully explore the environment of the Eath-Moon space and not to fly to the moon so quickly, then to the base of the above minimum velocity the probe can be guided faster to the moon with light pressure. For this reason, a large solar energy sail with a special normal needs to be installed on the probe. In this way, the purpose of exploring the Earth-Moon space can be attained and the flight will not spend a very long time.　　The results of computations show that the above-stated plan is effective. If the section area of the solar energy sail is large enough (provided that it can be implemented by techniques), then without any power the probe can be guided to the moon with light pressure just like a space sailboat.