载人航天是集国家政治、军事、科技实力为一体的高难度系统工程。要真正把人送入太空乃至使人长时期在太空生活,必须要突破三大技术难题。 第一难题:研制出推力足够大,可靠性极端好的运载工具。前苏联发射载人飞船的运载火箭都是运载能力 Manned spacecraft is a highly systematic project integrating political, military and scientific and technological strength in the country. To really bring people into space and even make people living in space for a long time, we must break through the three major technical problems. The first problem: developed a thrust enough, the reliability of extremely good delivery. The launch vehicles that formerly launched the Russian spacecraft were all carrying capacity