CNN
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Aluminum rocket and steel skyscraper. Smooth high-speed shuttle and glass facade. That’s how “the future” has been imagined for decades.
But that’s not what Kouji Murata imagines. Murata, a researcher at Kyoto University in Japan, has been studying how biological materials can be used in space.
Murata wondered, “Would it be possible to build a wooden house on the Moon or Mars?” and decided to test his theory. wooden satellite.
Recent National Oceanic and Atmospheric Administration research NOAA has found that 10% of atmospheric aerosols in the stratosphere contain metal particles from spacecraft, including satellites. The long-term effects of these pieces of metal are unknown, but scientists are concerned that they could damage the Earth’s fragile ozone layer.
Murata says wooden satellites would provide the same functionality as metal satellites but be better for the planet.
“At the end of its life, the satellite re-enters the atmosphere. The difference is that the wood inside LingoSat burns and ends up becoming a gas, but the metal becomes fine particles instead,” Murata said. Masu.
This is no mere pipe dream. Murata and his team have been working on this project for his four years, and he sent wood samples into space in 2021 to test the material’s resilience to space conditions.
Now they are In cooperation with Japan’s space agency (JAXA) and NASA, it plans to send a prototype satellite called LingoSat into orbit early next year.
magnolia, cherry, birch
For Murata, who heads the Space Wood Project at Kyoto University, wood is the obvious choice for space structures.
“When we use wood on Earth, we have problems with it burning, rotting, and deforming, but in space we don’t have those problems. There’s no oxygen in space, so it doesn’t burn, and there’s no living things.” Live in it,” he says.
Kyoto University
Kyoto University engineers are building a wooden satellite that will be launched into space in a joint mission with JAXA and NASA.
Murata added that wood has the same strength per weight as aluminum, making it an attractive option for space construction. The researchers’ tests on the International Space Station showed that wood is remarkably resilient in space.
For the satellite, Murata tested three types of wood. Commonly found in East Asia, Japanese cherry and Magnolia obobata are species native to Japan. Hinoki and cedar are commonly used for construction, but because the satellite is small, the research team “chosen materials that could withstand as much detailed work as possible,” Murata said.
In the end, the magnolia tree won out. Because its cells are small and uniform in size, they are easier to process and less likely to crack or break. Say.
Humans have been putting satellites into orbit since the 1950s, and up to 100 spacecraft were launched each year until 2010. However, over the past decade this number has increased as commercial launches have become easier. increased dramatically, Over 1,400 new satellites in 2021. The number of rockets sent into space is likely to continue to increase, with a NOAA study predicting that half of atmospheric aerosols in the stratosphere could contain metal particles from spacecraft in the coming decades. .
Other organizations are also considering the use of wood in space.
Finnish startup Arctic Astronautics has designed WISA Woodsat, a wooden satellite that was scheduled to be launched into space in 2021. But company founder Jari Mäkinen says the launch is hampered by bureaucratic hurdles.
“The satellite is ready and waiting to be disassembled and reassembled when the time comes,” Mäkinen told CNN in an email, adding that once the company receives a space operations license, the satellite will become a commercial It added that it would be launched using the rocket sharing service Rocket Lab.
Kyoto University
The satellite is made of magnolia wood and was tested on the International Space Station using two other types of wood.
At Khalifa University in the United Arab Emirates, aerospace engineer Yarjan Abdul Samad focuses on graphene as a potential material for space objects.
Samad is researching “nanowood,” a low-density wood combined with graphene to improve strength. Samad agrees with Murata that wood, a renewable, low-density material, has the potential to build not only satellites but also future space structures.
“There are a lot of research (projects) going on in space agriculture,” Samad said. “If we have wood grown in space, it could be used for manufacturing in space.”
However, there are still many unknowns about wood for space structures, says Tatsuto Fujita, a JAXA engineer who has been involved in studying the LingoSat project.
“From a Sustainable Development Goal perspective, it makes sense to use natural resources for space hardware, but since wood has never been used in satellites, what benefits are there at this point? I don’t know if I’ll get it,” Fujita said.
Safety is a top priority for JAXA and the J-Cube program, an effort to launch the satellite, and LingoSat passed preliminary evaluation without any significant concerns, Fujita said. “JAXA is also aiming to create lighter and stronger structural materials that are less likely to generate debris, and we are conducting research to achieve this goal.”
LingoSat is in final stages of safety review Scheduled to be launched in summer 2024 as a joint mission by JAXA and NASA. Murata said he plans to monitor the satellite for at least six months to see how it performs under space conditions, such as the extreme temperature changes in space.
Researchers plan to monitor the satellite orbiting Earth for at least six months, as shown in this rendering.Credit: Kyoto University
“At temperatures between -150 and 150 degrees Celsius (-238 and 302 degrees Fahrenheit), there is not much of a loss in strength, and we have confirmed that in experiments,” says Murata. “However, as satellites orbit the Earth, they experience such large temperature differences over the course of 90 minutes. We don’t know how well satellites can withstand these violently repeated cycles of temperature differences, so this needs to be investigated.” .”
The researchers will also monitor how the satellite reacts to radio waves and magnetic fields, and how the wooden shell protects the satellite’s semiconductors and chips.
In theory, wood should be a cheaper material to manufacture, but as it is a new technology, costs are still being evaluated, Murata said.
So far, very few materials have been used in space missions or objects, Murata said. He hopes his research and his LingoSat can show the potential of other, lower-impact materials.
“It’s a renewable material that’s kind to the environment and people,” says Murata. “I think wood can be used in space development, especially as interior materials and radiation shielding materials for small satellites and manned spacecraft.”