(一)人造卫星重量不断增加世界上第一颗人造地球卫星是前苏联在1957年10月4日发射的,接着美国、法国、日本以及我国也先后发射了自制的多种人造卫星,其中有些已按要求返回地面,有些已失效或坠毁,但目前仍有几千颗各种用途的人造卫星,在各自的轨道上围绕着地球运行。这些人造卫星中有些是为舰船、飞机、导弹等提供导航服务的,称为导航卫星;为气象预报服务的,称为气象卫星;为通信服 (1) Satellite Satellites Are Increasing in Weight The first man-made satellite in the world was launched by the former Soviet Union on October 4, 1957. Then the United States, France, Japan and China also launched a variety of homemade satellites successively. Some of them Have returned to the ground as requested, some of which have lapsed or crashed, but at present there are still thousands of satellites of various uses running around orbiting Earth in their respective orbits. Some of these satellites provide navigation services for ships, aircraft and missiles, and are called navigation satellites. They serve meteorological forecasts and are called meteorological satellites.