对人类来说，近距离的星际旅行早已实现──那就是各国正在发展的航天工程。但这类工程究竟有哪些意义呢？ 首先，工业化和商业化的应用前景十分诱人。太空的微重力、高洁净、全真空特殊环境，已被证实为人类最理想的工业加工地。 俄、美两国均在空间站或航天飞机上建立专门的 For humans, close-knit interstellar travel has long been realized - that is, the development of aerospace projects in various countries. But what exactly does this kind of project mean? First of all, the prospect of industrialization and commercialization is very attractive. Micro-gravity space, high purity, full vacuum special environment, has been proven to be the best man-made industrial processing. Russia and the United States both set up special stations in space stations or space shuttles