Japan poised to build world’s first wooden satellite

Japanese scientists are building the world’s first wooden satellite in an attempt to reduce the pollution of space with metal junk.

Wood is more easily penetrated by radio waves, so the satellite’s metal communication equipment can be carried inside the magnolia shell. Picture: Kyoto University

Japanese scientists are building the world’s first wooden satellite in an attempt to reduce the pollution of space with metal junk.

The LignoSat, which will be made of magnolia wood and can fit in the palm of the hand, is expected to be launched on a US rocket as early as the northern summer. The project, by a team from Kyoto University and the commercial company Sumitomo Forestry, follows a successful experiment in 2022 when samples of wood were exposed to the rigours of space for nine months on the International Space Station.

Wood does not burn in space because of the lack of oxygen, and the absence of micro-organisms means it does not rot either. The ISS tests revealed that it is also remarkably resistant to extremes of temperature and does not change in structure in a zero-gravity vacuum.

“Building in space with futuristic, space-age materials might seem to be the obvious choice: lumber’s fragility and combustibility might seem counterintuitive by comparison,” Kyoto University said in a statement.

“Therein lies the rationale for wood: as a natural, economical, carbon-based material, its production is considerably more sustainable than advanced alternatives, and its disposal, especially when dropped from orbit into the upper atmosphere, is complete and without harmful by-products.

“Despite the extreme environment of outer space involving significant temperature changes and exposure to intense cosmic rays and dangerous solar particles for 10 months, tests confirmed no decomposition or deformations, such as cracking, warping, peeling or surface damage.”

A wooden satellite will burn to biodegradable ash when re-entering the atmosphere. By contrast, aluminium satellites break up into small particles considered a dangerous pollutant, capable of causing damage to other space vehicles and potentially the ozone layer.

Wood is also more easily penetrated by radio waves, meaning that the satellite’s communication equipment, which will still be made of metal, can be carried inside the magnolia shell.

There are close to 10,600 satellites orbiting the Earth, 3000 of them defunct, a total mass of more than 11,000 tonnes. About 2500 new satellites are expected to join them every year over the next seven years.

THE TIMES