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China uses tow sails to successfully clear space debris

Chinese space scientists have said they have successfully deployed a giant space sail to clear debris from Earth’s orbit.

As announced by the Shanghai Academy of Spaceflight Technology on July 6, the giant sail was launched and successfully deployed to de-orbit the Long March 2 rocket.

The sail is made of an incredibly thin membrane, one-tenth the diameter of a human hair, and measures about 270 square feet. When attached to the Long March 2 rocket, it served to increase the atmospheric drag acting on the rocket, speed up the process of orbital decay, and de-orbit it faster.

According to Interesting Engineering, the sail’s material is inexpensive, flexible and lightweight, meaning it can be easily manufactured and launched to remove any form of space debris from orbit.

Of the almost 5,000 satellites that are still in orbit around the earth, only around 2,000 are still operational, so that the rest are now classified as space junk. There are also up to 27,000 smaller pieces of debris, also tracked by NASA, clogging the orbital zone and moving extremely fast — 15,700 miles per hour in low Earth orbit. The more things we send into orbit, the more likely they are to collide, which in turn creates a large number of additional chunks of space junk. In 2009, a defunct Russian spacecraft collided with a commercial US spacecraft Iridium, adding 2,300 large trackable debris and countless other smaller debris to the already busy orbit.

space junk
Stock image of space debris orbiting the earth. The tow sail is intended to accelerate the removal of space debris from orbit.
iStock/Getty ImagesPlus

Space debris has the potential to be lethal in future space missions. While small pieces of debris floating around far away don’t seem to be a big problem, in March 2022 a fast-moving chunk of a Chinese rocket slammed into the moon’s surface. If it had hit the International Space Station (ISS) instead, it could have been catastrophic. Since 1999, the ISS has had to perform 25 maneuvers to avoid being hit by approaching debris. Even if space debris hits something that humans don’t live on, the consequences could be dramatic, as we depend on satellites for a multitude of things, from communications and navigation to search and rescue and weather monitoring.

Finally, while everything in orbit around Earth eventually falls to the ground, once an orbit decays naturally, this can take a very long time, especially if they are orbiting far from Earth. Space junk in high Earth orbit about 22,000 miles away can take hundreds or even thousands of years to fall back to Earth. This sailing technology aims to speed up the orbital decay process, which means we can remove debris from orbit faster and hopefully ensure the safety of future spacecraft and astronauts.