Satellites that are no longer in service must get out of the sky far more quickly under a new rule adopted by US federal regulators Thursday — and it’s all in the name of combating the garbage in Earth’s orbit. Unused satellites in low-Earth orbit, which is the area already most congested with satellites, must be dragged out of orbit “as soon as practicable, and no more than five years following the end of their mission,” according to the new Federal Communications Commission rule. That’s far less time than the long-standing rule of 25 years that has been criticized as too lax. Even NASA advised years ago that the 25-year timeline should be reduced to five years. “Twenty-five years is a long time. There is no reason to wait that long anymore, especially in low-Earth orbit,” FCC Chairwoman Jessica Rosenworcel said at Thursday’s meeting. The FCC rule passed unanimously. The goal of this rule is prevent the dangerous proliferation of junk and debris in space. Already, there’s estimated to be more than 100 million pieces of space junk traveling uncontrolled through orbit, ranging in size from a penny to an entire rocket booster. Much of that debris, experts say, is too small to track. Collisions in space have happened before. And each collision can span thousands of new pieces of debris, each of which risk setting off even more collisions. One well-known theory, called “Kessler Syndrome,” warns that it’s possible for spaceborne garbage to set of disastrous chain reactions, potentially causing Earth’s orbit to become so cluttered with junk that it could render future space exploration and satellite launches impractical and even impossible. More than half of the roughly 10,000 satellites the world has sent into orbit since the 1950s are now obsolete and considered “space junk,” Rosenworcel said, adding that the debris poses risks to communication and safety. The FCC plan had been questioned by some US lawmakers who have said the rules could create “conflicting guidance” and without clear congressional authority. But Thursday’s vote moved forward nonetheless. “At risk is more than the $279 billion-a-year satellite and launch industries and the jobs that depend on them,” according to an FCC document released earlier this month. “Left unchecked, orbital debris could block all of these benefits and reduce opportunities across nearly every sector of our economy.” The number of satellites in low-Earth orbit, which is the sphere of orbit extending about 2,000 km or 1,200 miles out, has grown exponentially in recent years, thanks in large part to massive, new “megaconstellations” of small satellites pouring into space, largely by commercial companies. Most notably, Elon Musk’s SpaceX has launched about 3,000 satellites to space for its space-based internet service, Starlink. There’s also plans to put tens of thousands of new satellites in low-Earth orbit in years to come, FCC commissioner Nathan Simington noted during Thursday’s meeting. Commercial companies have routinely promised to take the debris issue seriously, and SpaceX had already agreed to comply with the recommended five-year rule for getting defunct satellites out of orbit. But there has long been a broader push within the space community to codify new regulations. So the FCC announced plans in early September to at least vote on updates to US regulations. The FCC also specified that it will apply the rule not only to the US satellite operators it oversees but also to “non-US-licensed satellites and systems seeking US market access.” “A veritable Cambrian explosion of commercial space operations is just over the horizon, and we had better be ready when it arrives,” said Simington.