The earth's gravity slows the moon's rotation, matching it to the speed of its orbit.
地球引力减缓了月球的自转速度,使之与其轨道的速度相匹配。
2
The mirrors could orbit—thousands of miles high—at the same speed as the earth turns on its axis.
这些镜子可以在几千英里的高空以地球绕地轴旋转的速度运行。
3
And the weight of the spacecraft orbit, the rocket needed to provide energy and speed varies, with a variety of track between the speed of a certain relationship.