LignoSat, the world’s first wooden satellite, has officially arrived at the International Space Station (ISS). The small Japanese spacecraft made its journey aboard a SpaceX Dragon cargo capsule on November 5. Developed by Kyoto University in collaboration with Sumitomo Forestry, LignoSat is not just a pioneering experiment with alternative materials—it could also mark a significant leap forward in sustainable space exploration. The 10-cm³ satellite, made from honoki magnolia wood, may offer a new approach to satellite design and disposal, with a focus on environmental responsibility.
The idea for a wooden satellite was first proposed in 2017 by Takao Doi, a former NASA astronaut and current professor at Kyoto University. Inspired by his discussions with forest scientist Koji Murata, Doi envisioned using wood as an alternative material for space exploration. The decision to use wood is backed by several factors: in space, where there is no air or water, wood is surprisingly durable. Moreover, wood is a biodegradable and renewable material, making it a more eco-friendly option compared to conventional metals used in spacecraft. This could address the growing issue of space debris, which currently poses a risk to active satellites and spacecraft.
One of the key advantages of wooden satellites is that they would disintegrate upon reentry into Earth’s atmosphere, leaving minimal environmental impact. In contrast, metal satellites burn up and release aluminum oxide, a substance that contributes to ozone depletion. Wood, being natural, would break down without leaving such harmful residues. Additionally, researchers hope that wood’s unique properties might even offer radiation shielding benefits—an important consideration for space missions.
In 2022, Doi and Murata’s team tested three types of wood—honoki (Japanese magnolia), cherry, and birch—to determine which would best withstand the harsh conditions of space. After subjecting the materials to extreme cosmic rays, solar radiation, and temperature fluctuations, the team concluded that honoki magnolia was the most resilient. Not only did it resist cracking under intense conditions, but its structure also allowed for precision construction using traditional Japanese joinery techniques called sashimono, which eliminates the need for screws, nails, or glue.
LignoSat’s wooden construction offers the added benefit of natural protection against cosmic radiation. If the experiment proves successful, it could pave the way for wood’s broader application in space technology and other industries. The satellite is expected to be released into space in December, where it will orbit Earth at an altitude of about 250 miles. During its mission, it will endure extreme temperature variations, swinging between -100°C and 100°C every 45 minutes as it transitions between sunlight and shadow.
In a press briefing on November 4, Meghan Everett, deputy chief scientist for NASA’s ISS program, acknowledged that the concept of using wood in space may seem unconventional. However, she emphasized that the research aims to demonstrate how a wooden satellite could be more sustainable and less polluting than traditional metal alternatives, offering a cleaner path forward for space exploration.
