When satellites burn up in the atmosphere, they don't entirely disappear. Tiny pieces of aluminium remain, contributing to an increasing mass of space junk. According to Daniel Oltrogge, director at the Center for Space Standards and Innovation, there are an estimated 760,000 objects larger than a centimeter (0.4 inches) now in orbit around Earth, much like the one that took a chip out of the International Space Station in 2016, per Business Insider. That's in addition to 6,000 satellites, 60% of which no longer work. With another 15,000 satellites for communication, TV, navigation, weather forecasting, and more, expected to launch by 2028, Japan is looking for a solution. And the result, according to the BBC, could be the world's first satellites made of wood.
"We are very concerned with the fact that all the satellites which re-enter the Earth's atmosphere burn and create tiny alumina particles which will float in the upper atmosphere for many years," says Takao Doi, a Japanese astronaut and professor at Kyoto University, which is working with Sumitomo Forestry to develop wooden satellites that would eliminate that problem. Sumitomo Forestry says it’s researching wood materials that are resistant to temperature changes and sunlight. Though those specific materials are a "secret" for now, the BBC reports the satellites could be ready as soon as 2023. That's around the time Japan will begin equipping its satellites with US sensors to monitor space debris, reports the Japan Times. (Japan previously launched a whip for space junk.)