Technology helps China become the first country to plant a flag on Mars

Chinese experts revealed the flag-making materials and technology that the Tianwen 1 landing station used to raise the flag on Mars last year .

On May 15, 2021, after a journey of about 500 million km lasting more than 300 days , the Tianwen 1 landing station landed on Mars and raised its national flag - making China the first country to plant a flag on the red planet, SCMP reported on September 28. The flag is made of smart fabric and can move gently in the Martian wind .

The Tianwen 1 lander drops the Chinese flag on the surface of Mars. (Photo: Harbin Institute of Technology).

In research published in the journal Advances in Mechanics , Chinese scientists reveal details about the flag-making materials , expected to be used in interplanetary travel, asteroid exploration and space projects. other.

The device carrying the Chinese flag is very light, less than 200 grams, and there are no motors or gears involved in the process of unfurling the flag. Critical moving parts are made from a smart polymer that changes shape when heated.

The device holds the rolled up flag with a pair of clasps made from a rubber band-like material. When heated , the clasp's "fingers" stretch and release the flag, allowing the flag to fall and unfurl naturally thanks to gravity.

The image of the American flag printed on the Japanese Hayabusa robot first appeared on the surface of Mars in 2008. The stars and stripes pattern reappeared during the Curiosity robot mission in 2012. In 2020, the American flag was printed on the Perseverance robot landing on Mars. However, such printed images do not meet the exact definition of a flag, which is usually made from fabric or similar material.

"The flag-raising on the lander made China the first country in the world to apply a smart structure based on shape-memory polymer composite materials to the mission of deep space exploration ," said the scientist. Leng Jinsong and colleagues at Harbin Institute of Technology said. Polymers can change shape freely but will return to their "memory shape" under the influence of heat, electric charge, magnetic force or chemical solution.

With continued funding from the government, Leng's team has spent more than two decades improving the performance of smart polymers. They add carbon fiber to strengthen the material. They also introduced a new theory to predict materials behavior, tested potential materials in some of the harshest environments, and worked with factories to reduce the cost of mass production.

"This technology is expected to be used in the Chinese space station, lunar exploration project, crewed space travel, exploration of Mars, Jupiter, asteroids, ice giant planets and other major aerospace engineering projects ," the research team said.

China plans to carry out several major space infrastructure projects, including a solar power station that can transmit high energy to Earth. These projects have previously been considered too large, expensive and complex, but smart materials could significantly reduce their costs and risks.