The Space Age began in 1957, when the Soviet Union launched humankind’s first artificial satellite, and the resultant Sputnik Shock set off the first wave of space exploration. In the intervening years, of course, the situation has changed dramatically. China and India currently have burgeoning space development programs, and private enterprises around the world have come to play a significant role in what was once the provenance of nation states alone. In the United States, private enterprise plays an increasingly independent role in advancing space development separately from defense and military programs. In contrast, the governments of China, Russia, and India oversee all aspects of space development in those countries. In Japan and throughout Europe—France, Germany, and Italy, in particular—space development is undertaken jointly by both the government and private enterprise. The 21st century has seen the testing of prototype reusable rocket systems as well as proposals for unprecedented, large-scale initiatives, such as a manned mission to Mars, an asteroid retrieval mission, and a space hotel concept. Also, microsatellites for Earth observation are a typical example of the kinds of inexpensive, small-scale projects for space development and utilization that have become practicable. Meanwhile, with Russia and China seeking to develop both offensive and jamming capabilities, increased space utilization complicates security issues. Space debris is another emerging issue that threatens the safe use of outer space. All of which makes the creation of rules and international norms for space utilization an issue of ongoing concern. 〔The table of contents and the summary in English are contained in the following document. https://doi.org/10.11501/10314924〕