2.06.2023

Wooden satellites? Yes. Wooden satellites.

A notional illustration of a satellite covered in wood and leaves. (Image credit: KyotoU Global Comms/Jake Tobiyama)

A team of researchers want to put a wooden satellite into orbit.

It's not as outrageous as you might think. Results from a recent test aboard the International Space Station (ISS), which exposed different woods to the vacuum of space, have been confirmed by the project's research team at Kyoto University, in Japan. Sure enough, the findings indicated that wood is remarkably resilient even in the environment of outer space.

"Despite the extreme environment of outer space involving significant temperature changes and exposure to intense cosmic rays and dangerous solar particles for ten months, tests confirmed no decomposition or deformations, such as cracking, warping, peeling, or surface damage," a recent Kyoto University press release said.

The experiment served as a preliminary investigation for the Kyoto University-led international partnership LignoSat, which designed a wooden satellite scheduled to be jointly launched by the Japanese space agency (JAXA) and NASA sometime next year. 

The LignoSat Space Wood Project began in April 2020, as a collaboration between Kyoto University and Sumitomo Forestry. "Wood's ability to withstand simulated low earth orbit - or LEO - conditions astounded us," Koji Murata, head of the space-wood research effort, said in a 2021 press release. "We … want to see if we can accurately estimate the effects of the harsh LEO environment on organic materials."

To test those effects, a small panel containing three different wood samples was launched to the ISS for stowage on the station's Japanese Experimental Kibo Module, where it was exposed to space for ten months in 2022. The wood panel was retrieved by JAXA astronaut Koichi Wakata and returned to Earth aboard SpaceX's CRS-26 cargo Dragon spacecraft in January 2023, and project scientists are hailing its success.

Of those woods tested, the LignoSat team chose to move forward with the project using the wood from Magnolia trees, because of its "relatively high workability, dimensional stability and overall strength," according to the release.

If in fact wood turns into a truly viable alternative for satellite manufacturing, it does have some potential benefits compared to the typical metal alloys used in today’s constructions. For one, it is more environmentally friendly, across the board. It is easier, cheaper and cleaner to produce, and is much more disposable when it comes to a satellite's end-of-life. 

When deorbited, satellites and the components from which they are assembled usually burn up mostly, if not entirely in Earth's atmosphere. The parts that don't burn up are strategically deorbited to splash down in remote parts of the ocean. 

Wooden satellites would most certainly completely burn up during atmospheric reentry, and if some small, fictitious fragments of wood somehow did survive the fiery plunge, they would be easily decomposed wherever on Earth they landed. 

Quelle: SC