a new generation of wooden satellites is about to be launched

The reason is ecological, satellites do not last forever and debris risks degrading the ozone layer. While these magnolia wood satellites, developed by Japanese researchers, will burn completely, without leaving any harmful residue.

A new generation of satellites is about to be launched. Satellites of a new kind made entirely, not of metal or plastic as usual, but of magnolia wood. The first in the world, called Lignosat, has just been assembled by the Japanese from the start-up Sumitomo Forestry and researchers from the University of Tokyo. It will be put into orbit in September by a SpaceX launcher. Why make it out of wood? For ecological reasons.

Satellites do not last forever; at the end of their life, they are destroyed by sending them to burn up in the atmosphere. Problem: some pieces can sometimes fall back to Earth, which can be dangerous. But above all, when burning in the atmosphere, their metal shell releases particles, particularly aluminum, which can end up damaging the ozone layer. Whereas with a wooden satellite, we are sure that it will burn completely, without leaving harmful residues (CO2 poses fewer warming problems in the upper layers of the atmosphere).

A priori, the satellite will also be resistant to space temperatures. Several species of wood have already been tested on the International Space Station. This is also what made it possible to choose magnolia for its resistance. In space, temperatures can vary between -120°C in the shade and +150°C in direct sunlight. The sending of this first satellite will therefore be an opportunity to verify that it is capable of withstanding extreme temperature changes.

Another advantage of wood is that, unlike metal, it does not block electromagnetic waves. We can therefore keep the antennas inside the enclosure. No need for articulated arms or shielding, simplifying design. The experiment should therefore be closely monitored. Because if it works, wood could well become the standard on future satellites.

This satellite pollution is, today, derisory. But a study by the World Economic Forum estimates that over the next decade, 990 satellites should be launched each year. In particular to strengthen Starlink type megaconstellations. Everyone will end up, one day, falling back into the atmosphere, so we might as well anticipate.