This is not just playing house, wooden satellites can also fly into space!

Popular Science Times reporter Chen Jie

This is not just playing house, the wooden satellite actually flew into space!

On November 4, the world's first wooden-shelled satellite, LignoSat, was successfully launched into orbit on a cargo ship of the US Space Exploration Technology Company. This small satellite, weighing only one kilogram, shows people that in the current rapid development of commercial aerospace, cost and sustainable development have been put on the "agenda".

"Artificial satellites play an important role in many fields such as human exploration of the universe, communications, and meteorological monitoring, and the selection of materials for their manufacture is even more critical." On November 6, Sui Tianyi, a professor at the School of Mechanical Engineering of Tianjin University, said in an interview with a reporter from Science Popularization Times that traditional artificial satellites are mostly made of metal materials such as aluminum alloys, magnesium alloys, and titanium alloys. These materials have high strength, high rigidity, and good radiation resistance, and can maintain stability in extreme space environments. However, with the continuous development of aerospace technology, exploring more environmentally friendly and sustainable materials for satellite manufacturing is becoming a necessity.

Judging from the success of LignoSat, wood is one option that has received much attention.

However, Yan Zhou, the overall structural designer of Micro-Nano Star, a commercial satellite manufacturing company, pointed out in an interview with reporters that after entering space, wooden materials will expand rapidly when exposed to the sun, and will shrink sharply when reaching the back of the earth due to being too cold. "Therefore, there are too many factors to consider in terms of craftsmanship when using wood to build satellites, and the cost of use will definitely not be low before large-scale application."

In this regard, Sui Tianyi introduced that as early as 2001, researchers began to study the impact of radiation on wood. In 2020, they brought wood to the International Space Station and conducted long-term space exposure experiments. "The experiment proves that wood can withstand the huge temperature difference test of up to 290 days in the space environment, and maintain good structural strength and stability in a strong radiation environment. Of course, for long-term satellites in orbit, the service stability of wood still faces huge challenges. Whether it can continue to "perform well" needs further exploration." Sui Tianyi emphasized.

Zhang Yousheng, director of the Micro-Nano Space Research Quality Department, also believes that wood has the characteristics of low cost and green environmental protection, allowing wooden satellites to burn completely in the atmosphere after completing their missions without leaving space debris. Its application in the aerospace field is an innovative breakthrough. "But it should be noted that wood has not achieved the alternative advantages of aluminum skin, composite materials, and 3D printed lattice structures in terms of material properties and processing characteristics. Whether it can be widely used still needs more in-depth analysis."

Perhaps there are still many pain points in building satellites with wood, but the success of LignoSat has actually pointed out the direction. In addition, among the many advantages of wooden satellites, good thermal insulation and electromagnetic wave penetration make the electromagnetic wave transmission inside and outside the satellite smoother, which is very friendly to the development of commercial low-orbit, short-period satellites.

"Of course, this characteristic also makes it impossible for satellites made of wooden materials to shield external electromagnetic interference, and other materials need to be introduced to cope with the influence of complex electromagnetic environments." Sui Tianyi said that currently the wood in wooden satellites mainly appears in the form of structural materials, and LignoSat only uses a wooden shell.

It is understood that LignoSat will operate in space for at least 6 months to monitor the stress, temperature and other changes of wooden structures in space, and transmit the data back to the ground for analysis. In this process, the wooden satellite will also fully demonstrate its stability and reliability in the space environment.

The innovation and potential advantages of LignoSat have attracted widespread attention. It is believed that more wooden satellites will join the ranks of space exploration in the future. "At present, green environmental protection has become a key topic of concern for researchers around the world, and using more natural materials in satellite manufacturing is also one of the topics. Using wood to build satellites is a good attempt at 'green spaceflight'," said Sui Tianyi.