A mini wooden satellite will soon be released into space for the first time. Integrated sensors will be responsible for evaluating the potential of the material in the space environment. But concretely, why turn to wood?
The world's first wooden satellite will be placed in orbit before the end of the year. It will be a CubeSat (a minisatellite) in the shape of a cube measuring about ten centimeters on each side, made largely of birch plywood. Only a few exterior parts (angles to facilitate its deployment once in space, and a selfie stick) will be made of aluminum.
This "Woodsat" was developed by Finnish science journalist Jari Makinen. “ I have always enjoyed making model airplanes, involving many wooden parts ” , explains Makinen. “ Having worked in space education, it made me wonder; why don't we fly wooden materials into space? » .
In 2017, Makinen had already enabled the deployment of a first wooden satellite (KitSat) in the stratosphere aboard a weather balloon. The next step will therefore be space, as originally planned.
For this mission, the CubSat will be launched aboard an Electron rocket from Rocket Lab. The European Space Agency (ESA), for its part, provides instruments and cameras to monitor the performance of the satellite in the space environment.
Of course, the wood will also be treated for the occasion. “ Ordinary plywood is too wet to be used in the space. This is why we will place our wood in a thermal vacuum chamber to dry it ” , says Woodsat chief engineer Samuli Nyman.
“Then we will lay down a very thin layer of aluminum oxide to minimize unwanted wood vapors (outgassing) in the space domain, while protecting it erosive effects of atomic oxygen (oxygen molecules broken down by ultraviolet radiation from the Sun) ”, continues the researcher. "We will also be testing other varnishes and lacquers on some parts of the wood .
If all goes as planned, this wooden satellite will be launched before the end of the year to be placed between 500 and 600 km altitude.
Efficacy, the question arises. Some had originally imagined this approach as a response to the growing problem of space debris in low Earth orbit. That said, whether metal, plastic or wood, these objects will always spin at the same speed (over 26,000 km/h) and will always represent a potential danger.
Could proposing wooden coatings allow better disintegration of satellites in the atmosphere, compared to traditional debris? Yes and no. These coatings might ignite more easily, but electronics will still be contained within. However, these compounds, sometimes toxic, will always be likely to further pollute our planet.
A possible benefit would be the radio's "transparency" from wood to airwaves. Concretely, satellite operators could keep most of their antennas indoors, which would limit the deployment of these instruments once in space… A delicate process that is the cause of the loss of many satellites.
