A Japanese research team consisting of timber company Sumitomo Forestry and Kyoto University has completed the first long-term trial of wood as a building material in space. As part of their research, various types of wood were tested on the International Space Station (ISS) for ten months to determine whether wood could be used for the construction of satellites. NASA has previously used balsa wood to wrap lunar probes, and in 2021, the Finnish Wisa Woodsat won an award for being the first wooden satellite. However, the Japanese team is the first to assess in detail the durability of wood as a building material in space.
The Japanese team tested various wood species, including the Honoki magnolia, Kamchatka birch, and mountain cherry, all of which grow in Japan. The samples were examined visually and microscopically for cracks, distortion, delamination, and surface abrasion. No damage was found in any of the wood species. The scientists and engineers also examined whether cosmic rays and atomic oxygen produced under solar radiation in low Earth orbit led to any chemical changes or decomposition of the wood. The researchers discovered that there was almost no damage caused by the environment in space.
In 2024, the Japanese team plans to build a wooden satellite using the wood of the Honoki magnolia. This wood was chosen because of its high workability, dimensional stability, and strength. The artificial satellite will be called LignoSat, with ligno meaning tree, and sat meaning satellite.
The Japanese astronaut Takao Doi proposed the idea of using wood as a building material in space and was appointed as Professor at Kyoto University Aerospace Exploration Research Unit in 2016. He began the research project on the applicability of wood in space, and the growth of trees under reduced gravity and low pressure. Sumitomo Forestry became involved in the project, hoping to gain insights for developing robust products on Earth. The Japanese timber group has previously claimed to have developed techniques to build 350-meter skyscrapers out of wood. In April, they announced that they would take part in the first earthquake test of a ten-storey wooden house.
Overall, the research on wood as a building material in space has shown that wood is a durable material that can withstand the harsh environment of space. The findings will be useful not only for building satellites but also for developing robust products on Earth.
