Featured keyword “space debris” |. Dai-ichi Institute for Economic Life Research

In April 2024, the National Aeronautics and Space Administration (NASA) announced that “space debris” thrown from the International Space Station had penetrated the roof of a private house in the US state of Florida. This debris refers to unnecessary man-made objects in outer space, such as used or damaged satellites, upper stages of launch vehicles, parts ejected during various missions, and fragments generated when these objects explode or collide. In other words, it is not something that originally existed in outer space, but something that was created as a result of human space exploration. There are said to be approximately 36,500 pieces of debris currently tracked from Earth that are 10 cm or larger, about 1 million pieces that are 1 cm or larger, and about 130 million pieces that are 1 mm or larger of this various sizes flying around the Earth. At a tremendous speed of 7 to 8 kilometers per second.

So what is the problem with debris? When debris collides with each other or with a satellite, many small pieces of debris are created. This collision may also lead to a new collision, in which case the number of debris will multiply to infinity. As a result, there are fears that the debris will fly through space at dizzying speeds, interfering with satellite operations or making it impossible to use outer space at all.

Since the launch of the world's first satellite in 1957, nearly 17,000 satellites have been launched into space, and there are about 9,000 satellites currently in operation. These satellites are used in many infrastructures such as communications, broadcasting, navigation, weather monitoring, disaster monitoring, defence, and traffic monitoring. When we talk about debris, it may seem as if we are talking about distant outer space that has nothing to do with our daily lives. However, given that the number of satellites ten years ago was only about 2,000, our lives are rapidly becoming powered by satellites. Efforts to sustainably use not only the Earth but also the outer space in which the Earth is located, i.e. preventing the increase of debris and removing the debris that is already there, is also a very important social issue.

(Mika Shishido, Policy Research Group, General Research Administration)