要使绕月探测卫星进入月球轨道,其速度应该达到多少呢?有人可能认为应达到11.2千米/秒的第二宇宙速度,实际上只要使初始速度大于10.6千米/秒(近地点600千米),绕月探测卫星就可飞向月球。这是由于月球本身处在地球引力范围内,当绕月探测卫星的飞行轨道在离月球6.6万千米之外时,主要受地球引力作用,是相对地球的椭圆轨道;在离月球6.6万千米之内以后,主要受月球引力作用,是相对于月球的双曲线轨道。 How fast should the moon orbiting satellites get into lunar orbit? One might think that a second cosmic velocity of 11.2 km / s is to be achieved, in effect only if the initial velocity is greater than 10.6 km / s (the perigee is 600 km ), Lunar exploration moon can fly to the moon. This is because the moon itself is in the sphere of gravity of the Earth. When the orbit of a lunar orbit satellite is 66,000 kilometers away from the moon, it is mainly gravitationally bound by Earth and is an elliptical orbit relative to the Earth. At a distance of 66,000 km from the Moon Within, mainly by the moon gravity, is the hyperbolic orbit relative to the moon.