人造地球卫星、宇宙飞船、航天飞机进入轨道后,其中的人和物将处于失重状态。人造地球卫星、宇宙飞船、航天飞机等航天器进入轨道后,可以认为是绕地球做圆周运动,做圆周运动的物体,速度的方向是时刻改变的,因而具有加速度,它的大小等于卫星所在高度处重力加速度的大小。这跟在以重力加速度下降的升降机中发生的情况类似,航天器中的人和物都处于完全失重状态。 Man-made earth satellites, spacecraft, space shuttle into orbit, one of the people and things will be in weightlessness. After spacecraft such as man-made earth satellites, spacecraft and space shuttle enter the orbit, they can be regarded as objects that make circular motion around the earth and do circular motion. The direction of the velocity is momentarily changed and thus has the acceleration, which is equal to the height of the satellite Gravity acceleration at the size. This is similar to what happens in a lift that descends at a gravitational acceleration, where people and things in spacecraft are in total weightlessness.