Sumitomo Forestry, a Japanese construction company, has teamed up with Kyoto University to begin developing wooden satellites resistant to UV damage and temperature changes, reports Justin Harper for BBC. The spacecraft will be the first Earth-orbiting wooden satellite.
Radio waves effortlessly pass through wood, so all communication antennas and sensors could be kept safely inside the satellite’s body instead of the outside like traditional metal satellites, reports the Economist. The researchers envision the satellite as a square with all the tech tucked inside.
Aside from more straightforward construction, the researchers say their main focus is to create a satellite that, upon re-entry into the Earth’s atmosphere, would burn up entirely and limit toxic particles released when a satellite falls to Earth. The wooden satellites may also help reduce space junk trapped in Earth’s orbit.
"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 professor of synergetic studies for space at Kyoto University, told the BBC. (Doi was the first person to throw a boomerang in space.)
There is some debate on whether wooden satellites would genuinely be sustainable, however.
The amount of orbital debris surrounding Earth—both natural and artificial—exceeded 8,000 metric tons as of January 1, 2020. The principal source of sizeable orbital debris comes from satellite crashes and explosions. Orbital debris, whether made of metal or wood, would still be space junk stuck orbiting Earth until something hits it out of the gravitational pull, explains John Timmer for Ars Technica. While the wooden satellites will not solve the space junk issue, it can provide new insight into material science.
However, little else is known about the project, reports Jennifer Leman for Popular Mechanics. Doi’s research team also hopes to study how wood reacts in space, specifically, in microgravity and under extreme temperatures, reports Popular Mechanics.
Although the team hopes to launch a wooden satellite prototype by 2023, it will not be the first wooden item in space. In the 1960s, a seismometer encased in a sphere made of balsa wood was designed for use as an impact limiter in NASA’s Ranger Block II spacecraft for the moon landing.