Japanese scientists have created one of the world's most unusual spacecraft, a small satellite made of wood.
the Lignosate probe It was built from magnolia wood, which, in experiments on the International Space Station (ISS), was found to be particularly stable and resistant to cracking. Plans are now being finalized to launch it on a US rocket this summer.
The wooden satellite was built by researchers at Kyoto University and the Sumitomo Forestry Company in order to test the idea of using biodegradable materials such as wood to see if they could serve as environmentally friendly alternatives to the metals from which all satellites are currently made. .
“All satellites that enter the Earth’s atmosphere burn up and produce small particles of alumina, which will float in the upper atmosphere for many years.” Takao DoiA Japanese astronaut and aeronautical engineer at Kyoto University recently warned. “Ultimately, this will affect the Earth's environment.”
To address this problem, researchers in Kyoto have set up a project to evaluate wood species to determine how well they can withstand the rigors of space launch and long journeys in Earth orbit. The first tests were conducted in laboratories that recreated conditions in space, and found that the wood samples experienced no measurable changes in mass or signs of decay or damage.
“We were amazed by the wood's ability to withstand these conditions,” said Koji Murata, project leader.
After these tests, the samples were sent to the International Space Station, where they underwent exposure experiments for about a year before being returned to Earth. Again, they showed few signs of damage, a phenomenon that Murata attributed to the fact that there is no oxygen in space that could cause the wood to burn, and no organisms to cause it to rot.
Several types of wood were tested, including Japanese cherry, with magnolia wood proving to be the strongest. This has now been used to build the wooden satellite in Kyoto, which will contain a number of experiments that will determine how well the spacecraft will perform in orbit, Murata said.
“One of the missions of the satellite is to measure the deformation of a wooden structure in space. Wood is strong and stable in one direction but may be subject to dimensional changes and cracking in the other direction.” observer.
Murata added that a final decision has yet to be made on the launch vehicle, with options now narrowed to a flight this summer on an Orbital Sciences Cygnus supply ship to the International Space Station or a similar SpaceX Dragon mission later in the year. The probe – which is the size of a coffee mug – is expected to operate in space for at least six months before being allowed to enter the upper atmosphere.
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If LignoSat performs well while in orbit, the door could open to using wood as a building material for more satellites. It is estimated that more than 2,000 spacecraft will likely be launched annually in the coming years, and the aluminum that these spacecraft are likely to deposit in the upper atmosphere as they burn up upon re-entry may soon pose major environmental problems.
Recent research conducted by scientists at the University of British Columbia in Canada revealed that aluminum from the re-entry of satellites could cause serious depletion of the ozone layer that protects the Earth from the sun's ultraviolet rays and could also affect the amount of sunlight that travels through the atmosphere and reaches… the earth.
However, this should not be a problem with satellites built of wood, such as LignoSat, which when they burn up during their re-entry into the atmosphere after completing their mission, will only produce a fine mist of biodegradable ash.