[News Terms] Japan's 'LignoSat' Scheduled for Launch This Summer

Wooden Satellite to Burn Up Upon Reentry into Earth's Atmosphere, Reducing Space Debris
To Be Launched on SpaceX or Cygnus, Mission Scheduled for 6 Months

'LignoSat' is a wooden satellite made from magnolia wood. It is an ultra-small satellite about the size of a coffee cup, measuring approximately 10cm in width, length, and height, and weighing around 330g. The name is a compound of the Latin word 'Ligne,' meaning 'wood,' and 'Satellite,' meaning 'artificial satellite.'

LignoSat was developed by the United States National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA) to enhance the sustainability of spaceflight. Wood does not burn or rot in space, but it incinerates into fine ash upon re-entry into Earth's atmosphere. This property is utilized to ultimately reduce the overflowing debris in Earth's orbit.

The world's first wooden satellite, 'LignoSat', a miniature satellite made of wood containing various equipment inside.
[Photo by Kyoto University, Japan]

In April 2020, NASA and JAXA launched the 'LignoStella Project,' aiming to launch a wooden artificial satellite, involving researchers from Kyoto University in Japan, the logging company Sumitomo Forestry, and Koroda Workshop, a Japanese furniture workshop with traditional joinery techniques.

The Kyoto University research team collaborated with Sumitomo Forestry to create and test samples from three types of wood?magnolia, wild cherry, and downy birch?to find the most stable and crack-resistant wood. The results showed that magnolia wood had the lowest likelihood of splitting or breaking and was superior in terms of workability and strength.

Currently, artificial satellites mainly use materials such as lightweight and durable aluminum alloys. Satellites that have completed their missions are designed to fall back into Earth's atmosphere to avoid becoming space debris. However, aluminum reacts with oxygen upon atmospheric re-entry to form aluminum oxide, breaking down into small particles that remain in the atmosphere for about 40 years. These particles accumulate in large quantities, reflecting sunlight and contributing to Earth's climate changes such as cooling.

It is known that more than 9,300 tons of artificial objects, including non-operational satellites, rocket bodies, separated fairings and boosters, and broken spacecraft fragments, are currently orbiting Earth as space debris. Space debris travels at speeds faster than bullets?7.4 km/s in low Earth orbit and 3 km/s in geostationary orbit?posing significant threats to Earth and operational satellites.

Illustration of LignoSat performing its mission.
[Photo by Kyoto University, Japan website]

In contrast, wood is composed of hydrogen, carbon, and oxygen, so when it enters the atmosphere, it leaves only water vapor and carbon dioxide, making it environmentally friendly. Additionally, wood allows electromagnetic waves to pass through, enabling antennas to be housed inside the satellite. Its physical properties remain stable from minus 100°C to plus 100°C, and it has very high stability and insulation. Since space lacks moisture, oxygen, and bacteria, wood neither burns nor rots.

According to major foreign media including the UK’s The Guardian on the 17th (local time), Japanese scientists are finalizing preparations for the launch of LignoSat. Based on their research results so far, the team plans to launch the world’s first wooden artificial satellite, LignoSat No. 1, this summer.

From March 2022, NASA and JAXA conducted a 'wood space exposure test' for 10 months aboard the International Space Station (ISS) using wooden satellite samples. In a statement last May, the research team said, "Testing three types of wood samples showed no deformation after space exposure," and "Despite being exposed to the extreme environment of space for 10 months, there was no cracking, warping, peeling, surface damage, decomposition, or deformation."

Although specific launch schedules have not been disclosed, it is reported that the satellite will be launched this summer aboard Orbital Sciences’ cargo spacecraft Cygnus or SpaceX’s Dragon transport vehicle. It will perform its mission in space for six months before re-entering the upper atmosphere and burning up, meeting its fate of complete incineration.

This content was produced with the assistance of AI translation services.