地球稠密大气层之外的空间区域,简称空间或外空,又称为宇宙空间或太空。在1981年召开的国际宇航联合会第32届大会上,陆地、海洋、大气层和外层空间分别称为人类的第一、第二、第三和第四环境。通常把100千米～120千米以下的大气层称为稠密大气层,也称为大气环境或人类的第三环境;而100千米～120千米以上称为外层空间或人类的第四环 The space area outside the dense atmosphere of the Earth, referred to as space or space, is also called space space or space. At the 32nd IAF Congress held in 1981, the land, sea, atmosphere, and outer space were called human first, second, third, and fourth environments, respectively. Generally speaking, the atmosphere below 100 km to 120 km is called the dense atmosphere, also known as the atmospheric environment or the third environment of human beings. The 100 km to 120 km above is called the fourth ring of outer space or human beings.