You might think metal satellites burn up on re-entry, but as it turns out, it’s not that simple. “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,” Takao Doi, an astronaut and Kyoto University professor, told the BBC when speaking about the project. “Eventually it will affect the environment of the Earth.”
Wood, however, would entirely burn up upon re-entry without leaving harmful substances in the atmosphere—or perhaps scattering dangerous debris. According to Nikkei Asia, another reason the researchers are experimenting with wood is that it doesn’t block electromagnetic waves or the Earth’s own magnetic field. That means wooden satellites could have simpler builds, as components like antennas could be placed inside the satellite itself.
According to the World Economic Forum, there are roughly 6,000 satellites currently in orbit, of which 60% are actually defunct. Meanwhile, 990 satellites are estimated to be launched every year for the next decade. The WEF also notes that there are more than half a million pieces of space trash larger than a marble currently floating around the Earth and 20,000 pieces of debris that are larger than a softball. These pieces of trash aren’t static. They are actually moving at speeds up to 17,500 miles per hour, the speed necessary to remain in orbit and not fall back to the Earth itself. According to NASA, more space junk presents an increasing danger of collision to all types of spacecraft, including the International Space Station, shuttles, and any other type of vessel that may carry humans.
The problem of space clutter is only getting worse, as both Elon Musk’s SpaceX and Amazon’s Project Kuiper race to launch thousands of satellites into orbit to provide low-cost internet. Meanwhile, astronomers have also expressed concern that these satellite constellations could potentially disrupt their ability to observe the cosmos. It’s unclear how much wooden satellites would alleviate the problem, but hey, it’s gotta be better than sticking more metal junk up there.