An international organization called ATC21S suggests “21st century skills” and states importance of merged skills which are not resolved into learning contents of each subject in school. It is difficult to enhance such skills by old unsystematic education among each subject. On the other hand, “STEAM education,” which is merged Science, Technology, Engineering, Art and design, and Math is attracting attention and is being promoted in the United States, Korea and other countries. It is thought that education into which several subjects are merged like STEAM education is effective in enhancement of merged skills like 21st century skills. The author explains the reason why “space science” is good for STEAM education in this article.