Wherever we humans go, we leave behind a mess. That goes for space, too.
Today, our species is responsible for more than 500,000 pieces of junk hurtling around Earth at phenomenal speeds, and if we don't start actively removing the largest pieces, the risk of collisions will only grow worse.
"Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water," says Jan Wörner, European Space Agency (ESA) director general.
"That is the current situation in orbit, and it cannot be allowed to continue."
It's almost as if we need a tow truck to remove all the thousands of failed satellites from our orbit; incidentally, that's exactly what the ESA is working on.
By 2025, the agency plans on launching the world's first orbiting junk collector, a four-armed robot that tracks down space waste like Pac-Man in a maze.
The first-of-its-kind mission, known as ClearSpace-1, will start out small, collecting only a single piece of space junk to prove the concept works. The target in this case is called Vespa, a leftover remnant from ESA's Vega rocket launch in 2013.
This piece of junk weighs roughly the same as a small satellite and has a simple shape that should make it easy to grab with four robotic arms. Once it's safely in the arms of the garbage collector, it will then be dragged out of orbit and allowed to burn up in the atmosphere.
Unfortunately, this will also destroy the collector, but in the future, the agency hopes to create a way for the robot to safely eject the rubbish and continue capturing and de-orbiting other pieces.
The ultimate goal is to create a spacecraft that can propel and direct itself in low orbit with a "high level of autonomy", according to the Swiss startup, ClearSpace, which is in charge of designing the machine.
"The space debris issue is more pressing than ever before. Today we have nearly 2,000 live satellites in space and more than 3,000 failed ones," says ClearSpace CEO Luc Piguet.
"And in the coming years the number of satellites will increase by an order of magnitude, with multiple mega-constellations made up of hundreds or even thousands of satellites planned for low Earth orbit."
Creating a network of garbage collectors for these satellites comes with its challenges. Powering a spacecraft, after all, costs a lot of money, and while scientists have been exploring cheaper options for years - like using the garbage it collects as fuel - nothing has so far come to fruition.
The ClearSpace mission is set to cost 117 million euro (US$129 million), but another company based in Tokyo called Astroscale may beat it to the punch. It plans on launching its first demonstrations within the year, but whether or not it can prove cost-efficient is another matter. Watch this space.
