Space junk has been a problem since space travel began: When Sputnik launched in 1957, it left behind part of a rocket. Now, decades later, hundreds of thousands of marble-sized pieces of satellites and spacecraft are orbiting around Earth. Since the trash is traveling at up to 17,500 miles per hour, even a tiny fleck of old paint can be enough to damage new space missions.
Last week, JAXA, the Japanese space agency, started testing one way to clean up the trash—a giant cable of wires that can sweep through space while generating an electric current. In theory, this will cause the debris to slow down, start to fall towards Earth, and then burn up as it reaches Earth’s atmosphere.
Unlike other attempts to clean up space, the tether is intended to be relatively cheap and simple to make. Two box-shaped spacecraft fly with the tether stretched out at nearly 1,000 feet. The tether itself is made of ultra-thin wires of stainless steel and aluminum, fabricated with the help of a Japanese fishing company (which also happens to be helping JAXA build a giant net, in another experiment in catching space debris).
Scientists worked on the tether for five years before launching it, and even now, the tether isn’t quite ready to actually do any cleaning: This launch will just test whether the tether can unfurl correctly and generate electricity. But the scientists also say it’s pretty critical that cleanup starts as soon as it’s possible.
"Space debris is expected to collide with and destroy drastically a satellite in operation or a defunct satellite once every four to five years," says Seishiro Kibe, the director of the Innovative Technology Research Center at JAXA. "If this is true, the number of pieces of space debris will continue to increase by the thousands in each collision. This will cause more frequent collisions ... This vicious cycle will continue endlessly unless we act to stop it, and the near-Earth environment would be so full of waste it would become irreparable."