Trees and forests have been used by humans for thousands of years for cooking, heating, building homes, furniture, railroads, and more. Now, researchers are aiming to push boundaries by transporting wood into space.
Japanese scientists are building the world’s first wooden satellite as an environmentally friendly alternative to the aluminum ones currently circling Earth. This is an attempt to reduce space pollution by metal junk and its potential effects on the ozone layer that contribute to climate change.
Why build a wooden satellite?
LignoSat is a coffee mug-size satellite made from magnolia wood (or Hoonoki in Japanese). U.S. space agency NASA and the Japan Aerospace Exploration Agency (JAXA) are preparing to launch the world’s first wooden satellite by the summer of 2024.
“Wood’s ability to withstand simulated low earth orbit — or LEO — conditions astounded us,” said Koji Murata, who is leading the space-wood research at Kyoto University.
Wood was chosen because it is a natural, cost-effective, carbon-based material. Its production is much more sustainable compared to advanced alternatives. Several types of wood were tested, including Japan‘s cherry and Erman’s birch. However, the wood from magnolia trees, used for knife handles to chopsticks, proved to be the most robust.
Additionally, wood decomposes entirely without producing harmful byproducts when disposed of, particularly when dropped from orbit into the upper atmosphere. Previous earth-based experiments showed wood’s remarkable resilience to temperatures ranging from -150 to 150 degrees Celsius and its minimal structural deterioration under simulated near-vacuum conditions.
Takao Doi, a Japanese astronaut and aerospace engineer at Kyoto University, cautioned about the environmental impact of traditional satellites. “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, a Japanese astronaut and aerospace engineer with Kyoto University, cautioned. “Eventually, it will affect the environment of the Earth.”
Wood Satellite project – eco-friendly space exploration
In April 2020, Kyoto University and logging company Sumitomo Forestry initiated the LignoStella Space Wood Project in collaboration with the Japanese space agency JAXA to test the durability of three different types of wood in space. In 2022, space exposure tests were conducted for over 240 days aboard the Japanese Experiment Module Kibo of the International Space Station (ISS). The wood samples exhibited no measurable changes in mass or signs of decomposition or damage during initial tests conducted in laboratories simulating space conditions.
“When you use wood on Earth, you have the problems of burning, rotting and deformation, but in space, you don’t have those problems: There is no oxygen in space, so it doesn’t burn, and no living creatures live in them, so they don’t rot,” according to Koji Murata.
With the 2024 launch of a wooden artificial satellite on the horizon, the research team is delving into the fundamental mechanisms of nano-level material degradation. Their discoveries hold promise for developing resilient and high-performance wood materials for innovative applications.
Clearing the cosmic clutter
A staggering 100 trillion untracked pieces of old satellites orbit our planet. This is expected to increase as the number of satellites in orbit is expected to increase from 9,000 today to over 60,000 by 2030. Scientists have called for a legally binding treaty to ensure Earth’s orbit is not irreparably harmed by the future development of the global space industry.
Researchers believe that a buildup of these particles could deplete the ozone layer surrounding our planet, which prevents ultraviolet radiation from reaching the surface. This radiation can cause cancer in humans and damage other animals and plants.
Wooden satellites offer the potential to mitigate both physical and optical pollution in Earth’s orbit. Biodegradable and less reflective, wooden satellites have the potential to address the space debris issue and also restore the natural beauty of the night sky. The key objective of the Japanese project is to explore environmentally friendly alternatives to the metals traditionally used in building satellites.
