Forestry companies and space agencies don’t cross paths too often, but Kyoto University and a company called Sumimoto Forestry have worked together to create the world’s first wooden satellite. The satellite will be sent to space on a SpaceX rocket from the Kennedy Space Center in September, bound for the International Space Station (ISS).
Wood, meet space
“Satellites that are not made of metal should become mainstream,” says Takao Doi, an astronaut and special professor at Kyoto University.
As strange as it sounds, wood may actually be a good material to send into space. Wood kept in space-like conditions seems to exhibit no mass loss or decay and it’s a sustainable resource. Upon re-entering the Earth’s atmosphere, wooden satellites are expected to burn up completely without leaving harmful residues, unlike metal satellites which can survive re-entry and contribute to terrestrial pollution and debris.
Another advantage of using wood over metal is that wood is essentially transparent to many wavelengths. This allows antennas to be safely housed within the wooden frame, eliminating the need for external antennas. Currently, when a new satellite is launched into orbit, it must deploy external antennas—a delicate process that can sometimes fail. Essentially, wood enables satellites to become simpler, cheaper, and less costly.
The new satellite, called LignoSat, has been four years in the making. It measures 10 cm (four inches) in all directions. Several different types of wood were trialed, with the engineers settling on magnolia wood. The satellite will now be shipped to JAXA (the Japanese space agency) and from there on, it will hopefully make its way to the ISS where its strength and durability will be checked.
“Data will be sent from the satellite to researchers who can check for signs of strain and whether the satellite can withstand huge changes in temperature,” a Sumitomo Forestry spokeswoman told AFP on Wednesday.
Satellites are a growing problem
If satellite pollution doesn’t sound like much of a problem, you’ve probably not been paying attention. The number of satellites has been skyrocketing in recent years and shows signs of increasing even faster. This is causing multiple issues.
For starters, space debris poses a significant threat to the International Space Station (ISS) and other manned missions. Even minor impacts can jeopardize the safety of astronauts and the integrity of the station. Then, the increasing number of satellites contributes to light pollution, which affects astronomical observations and the natural night sky. This is particularly problematic for ground-based telescopes and astronomical research. But where wood could really help is with the issue of decommissioning satellites.
With more satellites in orbit, we need to pay more attention to decommissioning them safely. De-orbiting satellites can survive re-entry and contribute to pollution in the Earth’s atmosphere and surface. Furthermore, the materials used in satellites can produce harmful residue and leave pieces behind.
“All the satellites which re-enter the Earth’s atmosphere burn and create tiny alumina particles, which will float in the upper atmosphere for many years,” Takao Doi, a Japanese astronaut and aerospace engineer with Kyoto University, warned recently. “Eventually, it will affect the environment of the Earth.”
Next steps
The researchers that designed LignoSat have tested wood in space before. Two years ago, the researchers exposed three types of wood to the harsh environment outside the ISS over a period of 10 months. If this newest test is successful, it may only be a couple more years before wooden satellites start being deployed.
“We would like to create a satellite, including the electronic substrate portion (contained inside), entirely made from wood in the future,” said Takao Doi.
