征服宇宙是人类永恒的梦想。随着国际空间站的建成,太空假期也成了最前卫的旅程。但在你做一切准备之前,首先来学习一个名词:微重力状态。当一切物体在进行航天飞行时,它们的重量都不见了,这种现象称为“失重”。其实完全失重是一种理想的情况,在实际的航天飞行中,航天器除受引力作用外,不时还会受到一些非引力的外力作用。例如,在地球附近有残余大气的阻力,太阳光的压力,进入有大气的行星时也有大气对它的作用力。根据牛顿第二定律,力对物体作用 Conquering the universe is an eternal dream of humankind. With the completion of the International Space Station, space holidays have also become the most avant-garde journey. But before you do everything, first learn a noun: microgravity. When all objects are in space flight, their weight is lost. This phenomenon is called “weightlessness.” In fact, total weightlessness is an ideal situation. In actual spaceflight, the spacecraft receives gravitational force and occasionally receives some non-gravitational external force. For example, there are residual atmospheric resistance near the Earth, the pressure of sunlight, and the force of the atmosphere on it when it enters the atmosphere. According to Newton’s second law, force acts on the object