在航天飞机的飞行轨道所处的220～1000千米高度的宇宙空间,每立方厘米只有10~(10)-10~(16)个空气分子,按物理学的概念这已经是空气极端稀薄的世界。可是,也正因为空气成分近乎为零,太阳射线、重粒子宇宙线等有害射线才得以肆意横行,造成了一种严重威胁生命安全的环境。宇航服就是在这种极端环境下穿用的特殊服装,造价昂贵也贵得其所。1984年2月7日,美国宇航员布鲁斯完成第1例太空行走时,身上那套无系索背包式宇航 In the cosmic space of 220-1000 km at the space shuttle’s orbit, there are only 10 to 10 to 16 air molecules per cubic centimeter. According to the concept of physics, this is already extremely thin air world. However, precisely because the composition of air is almost zero, harmful rays such as solar rays and heavy particle cosmic rays can be arbitrarily rampant, creating a serious threat to life and safety. Spacesuits are the special clothes worn in this extreme environment, expensive and expensive. February 7, 1984, the United States astronaut Bruce completed the first case of space walking, the body of that set of backless line astronautics