我们正生活在宇航时代,绕地球运行的轨道上挤满了人造卫星,如气象卫星、通讯卫星、间谍卫星和“哈勃望远镜”等等。人类发射的探测器有的正绕着火星的两极飞行,有的早已脱离了太阳系驶向茫茫银河的深处……在新世纪初,回眸人类探索太空的百年历史是很有意义的。 We are living in the aerospace era. The orbit orbiting the earth is full of artificial satellites such as weather satellites, communications satellites, spy satellites, and the Hubble Telescope. Some of the detectors launched by humans are flying around the two poles of Mars, and some have long since escaped from the solar system to the depths of the Milky Way. At the beginning of the new century, it is of great significance to look back at the century-long history of human exploration of space.