所谓黑障,是指当卫星、航天飞船、洲际导弹等飞行器以极高的速度再入大气层返回地球时,在一定高度和一定时间内,发生与地面通信联络严重失效甚至完全中断的现象,这是一种发生在大气层的特有现象,这就是黑障。黑障的范围取决于再入体的外形、材料、再入速度,以及发射信号的频率和功率等。黑障区给载入飞船再入返回时的实时通信和再入测量造成了困难。黑障区大约出现在地球上空35公里~80公里的大气层 The so-called black barrier means that when a satellite, a spacecraft or an intercontinental missile enters the atmosphere at an extremely high speed and returns to the Earth, it will seriously or even completely be interrupted during certain altitude and time. It is a peculiar phenomenon that occurs in the atmosphere. This is a black barrier. The scope of the black barrier depends on the shape, material, reentry speed of the reentry body, the frequency and power of the transmitted signal, and the like. The black-out area has caused difficulties in real-time communication and reentry measurements when loading spacecraft into and out of the area. The black-out area appears about 35 to 80 kilometers above the Earth’s atmosphere