目前,航天飞机只能把有效载荷送入低地球轨道。而从低轨道到静止轨道仍有相当一段距离,所以,放置在低轨道上的有效载荷还需要动力才能继续登攀,最后到达目的地——静止轨道。现在基本上有两种方法可使在低轨道上的卫星获得动力,进入静止转移轨道。一种是用麦克唐纳。道格拉斯公司研制的有效载荷辅助舱 At present, the space shuttle can only send payloads into low Earth orbit. However, there is still a considerable distance from the low orbit to the geostationary orbit. Therefore, the payload placed on the low orbit needs power to continue its climb and finally to the destination geostationary orbit. There are basically two ways to get the satellites on the low orbit into power and into the static transfer orbit. One is to use Macdonald. Douglas developed the payload auxiliary compartment