Over the weekend, Japan’s Kounotori 6 re-supply vehicle began a four-day journey to the International Space Station. At the end of that mission, it will begin its decent towards Earth, extending a cable as long as six football fields, which is designed to knock chunks of potentially harmful space debris out of orbit, reports Bill Chappell at NPR.

According to JAXA, Japan’s space agency, the anti-space junk measure—known as the Kounotori Integrated Tether Experiment (KITE)—will be tested for a week before Kounotori burns up in Earth’s atmosphere. The 2,296-foot line is weighted at its outer end by a 44-pound mass. Its movement through Earth's magnetic field generates an electric current that can help redirect space junk towards the lower atmosphere, where it is destroyed.

It's one of many projects aimed at dealing with space junk, a problem that is growing worse year by year.

NASA and the Department of Defense currently track 500,000 pieces of space debris in orbit, with 20,000 of those pieces larger than a softball. Over the decades, Earth has developed a blanket of space debris, including everything from paint flecks from spacecraft to used up rocket stages. And the problem is getting worse—in 2009 a defunct Russian satellite collided with an American satellite, creating 2,000 new pieces of space debris. In 2007, China used a missile to blow a satellite out of orbit, creating a 3,000-chunk mess.

The problem has gotten so bad that in 2011, The National Research Council announced that space junk has reached critical mass and that NASA and other space agencies have not acted quickly enough to address the problem.

“The current space environment is growing increasingly hazardous to spacecraft and astronauts,” Donald Kessler retired head of NASA's Orbital Debris Program Office and chair of the committee that authored the report said in a release. “NASA needs to determine the best path forward for tackling the multifaceted problems caused by meteoroids and orbital debris that put human and robotic space operations at risk.”

We’ve reached a critical threshold knon as Kessler Syndrome, according to Clara Moskowitz at Space.com. There is so much space debris that collisions between these bits and pieces will create more debris, resulting in a cascade effect that creates more and more debris. This process generates space junk faster than it decays, making working in orbit extremely hazardous.

Last year, NASA Administrator Charles Bolden admitted NASA is not moving quickly enough reports Michael Casey at FOX. “We are among those [space agencies] that’s not putting a lot of money into debris removal,” he said. “We work a lot on what we call debris mitigation, making rules that say when you put something in space it has to have enough fuel to, when its mission is over, you can either put it into a parking orbit where it won’t come back for a hundred years, or you can safely de-orbit it into the ocean. But that’s not the answer. The answer’s going to be debris removal, and we’ve got to figure out how to do that.”

There are many projects in development. The European Space Agency is considering a project called e.Deorbit, a satellite that would capture and redirect other satellites using a net or robotic arm, but that project won’t launch until 2023 at the earliest. Researchers at Texas A&M have come up with a concept that would capture and slingshot space debris towards Earth’s atmosphere. CubeSail is a project from the University of Surrey, which uses solar radiation pressure to power a large sail that would drag debris into lower orbit. None of those, however, are currently under construction, making the KITE program an important step toward cleaning up our mess in space.