So, if you have three satellites,

如果有三颗卫星
they can help you connect any point on the Earth to any other point

你就可以通过卫星的反射
by reflecting off the satellites.

在地球上任意点联系到任意其它点
But the important thing is,

但重点是
the satellites better be where you think they are.

卫星得呆在你认为它所在的地方
If they're constantly moving around, it doesn't work.

它们不能乱动
So, what you really want is

所以你真正需要的是
what's called geosynchronous satellites.

所谓的"地球同步卫星"
They are satellites--

这种卫星
remember, if I look at the Earth from the top,

记住如果从顶部看地球
it is spinning.

它是旋转的
This is the North Pole and they're spinning.

这是北极地球在旋转