Laser beams, wooden satellites or even space “tow trucks”: In Japan, scientists and start-ups are competing for projects to address the growing problem of space debris.
According to the latest estimates from the European Space Agency (ESA), one million pieces of waste – more than a centimeter – from used satellites or rocket bits – are already orbiting the earth at very high speeds.
And with the advent of “mega-constellations” of satellites aimed at providing fast and ubiquitous Internet access, this number is likely to grow disproportionately.
“We are entering an era where many satellites will be launched one after another. The space will become more crowded,” recalls Mickey Ito, leader of Astroscale, a young Japanese company working for a “sustainable” space.
“The simulations suggest that if we continue like this, the space will become unusable,” Ms Ito warned in an AFP interview. “So we need to improve the sky environment before it’s too late.”
Incidents are already on the rise: in January, a Chinese satellite was hijacked by a fragment of an old Soviet satellite. And last year, the robotic arm of the International Space Station (ISS) was punctured by a few millimeters of debris.
– Warning + near debris + “-
“Small debris is problematic because they are not listed,” explained researcher AFP Toru Yamamoto of the Japanese space agency Jaxar, as opposed to large objects, which have names and whose location and speed are “permanently marked”.
Good practice rules exist to limit space debris, such as removing life-end satellites to “cemetery orbit”. But this is not enough, especially since there is currently no legally binding international text.
“A geostationary satellite feels about 100+ debris + alerts every year,” Tadanori Fukushima, an engineer with Japanese satellite operator Sky Perfect JSAT, told AFP.
Mr. Fukushima has set up a start-up to dig a static-experimental solution: a laser beam that will evaporate the surface of space debris will create an energy vibration to transport objects to a new orbit.
He hopes to conduct the first test in space by the spring of 2025 in collaboration with various research institutes.
The concept of the astroscale is even more advanced: a kind of space “tow truck” works with the help of a magnet to recover the last satellites of life.
The company passed a first test last year and plans to make a second by the end of 2024 in partnership with British operators ESA and OneWeb, a constellation of low-orbital satellites.
– “There is no universal remedy” –
More unusual, another Japanese team envisions a wooden satellite, an element that would have the advantage of being completely swallowed up when re-entering the Earth’s atmosphere.
The project at the University of Kyoto (western Japan) and logging group Sumitomo Forestry is still in its infancy: in March, pieces of wood were sent to the ISS to test the response of cosmic rays.
Fukushima says Japan is one of the most dynamic space nations in the development of space debris solutions.
But according to this engineer, companies around the world are also in a race to conquer this nascent market, which could really grow by 2030.
Towards the end of 2020, ESA signed a 100 million euro agreement with ClearSpace, a Swiss start-up to send the world’s first commercial mission to clear space debris in orbit in 2025.
American companies such as Orbit Fab and Specialists (affiliates of aeronautics and defense group Northrop Grumman), or Australian Newman Space design various satellite repair services to prolong their use, for example with their fuel in space.
According to Jaxar Yamamoto, the space debris problem allows a wide range of complex solutions to coexist. “There is no universal remedy”.
kh / etb / mac / roc
Sky Perfect JSAT Holdings