Japan builds wooden satellite to reduce space debris

LignoSat is a project by a team from Kyoto University and the Sumitomo Forestry, a timber company, to create a self-destructing satellite to reduce space pollution.

The LignoSat satellite is about the size of a small coffee cup and is made from magnolia wood, which has been tested by astronauts on the International Space Station (ISS). They say it is extremely stable and has excellent resistance to cracking.

The research team said they wanted to use biodegradable, environmentally friendly materials such as wood to replace the metals that have long been used to create satellites.

Humans have launched nearly 13,000 satellites into space since 1957, but satellite tracking website Orbiting Now says only about 8,377 will still be operational as of February 3, 2024.

The remaining “dead” satellites are stuck in orbit, merging with other creatures and forming giant piles of waste.

According to the European Space Agency (ESA), the current amount of space junk is about 9,700 tons. This number will increase, especially when many powers are racing to explore space.

"All satellites burn up when they re-enter the Earth's atmosphere, creating tiny aluminum oxide particles. They will float in the upper atmosphere for many years, then affect the Earth's environment," said Takao Doi, a Japanese astronaut and aerospace engineer at Kyoto University.

To address this issue, researchers in Kyoto have launched a project to evaluate the durability of wood in the harsh conditions of space and long-distance orbits around the Earth. Wooden satellites would burn up upon re-entering the atmosphere, leaving behind only biodegradable ash.

The first tests were conducted in the laboratory. Then the wood samples were sent to the ISS for nearly a year and then returned to Earth. After this period, the wood samples showed very little sign of damage, possibly because there is no oxygen in space so the wood does not burn, and there are no living organisms so the wood does not rot.

After testing different types of wood, such as Japanese cherry, magnolia wood was found to be the strongest. This wood was then used to build Kyoto University's new satellite, according to Koji Murata, the project leader.

Unlike conventional satellites, the LignoSat wooden satellite will safely self-destruct on its way back to Earth's atmosphere.

Mr. Murata said that LignoSat will be launched into space by an American rocket and operate for at least 6 months.

Minh Hoa (reported by Dan Tri, Tuoi Tre)

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