The U.S. government is taking legal steps to limit the amount of space junk — the cloud of dangerous debris still orbiting the Earth — after more than six decades of space races, rocket launches, planetary missions and booming satellite activity.
The key measure is the imposition last week by the Federal Communications Commission of a five-year lifetime for new satellites after they complete their mission, by which time they’ll have to deorbit and burn up in the Earth’s atmosphere.
Before now, a 25-year lifetime has been in place as a guideline, but it’s never been legally enforced.
The new rule applies only to satellites launched by U.S. operators, and it won’t solve the space junk problem on its own. But experts agree it’s a good start and in line with international efforts.
“It’s about establishing rules for space and having a legal framework that people have to adhere to,” said space debris expert Carolin Frueh, an associate professor of aeronautic and astronautic engineering at Purdue University in West Lafayette, Indiana. “That’s a big step.”
Earth’s orbital space is vast, and there are only about 5,000 active satellites. But it’s estimated that there might be millions of pieces of space junk circling our planet — from entire stages of rockets, which can weigh several tons, to inactive satellites, lost bits of space equipment, stray nuts and bolts, and the broken fragments of orbital collisions.
Most of those pieces are tiny — smaller than a nickel. But they’re orbiting at more than 15,000 mph, and experts estimate there are about 30,000 pieces of space junk large enough and fast enough to be a serious problem — and potentially a disaster.
There have already been some close calls. In June the International Space Station changed its orbit to avoid debris from a Soviet-era satellite, which had been blown up in a Russian test of a new anti-satellite missile. So far the ISS has had to avoid orbiting space debris more than 30 times during its 23-year mission. It’s also been damaged by space junk, and on another occasion the ISS crew were ready to leave in case of a collision.
And the problem will get worse. One report estimated that about 10,000 more dangerous pieces of space junk will be in orbit by the end of this century.
“Space debris is not yet at the stage where we cannot do any more space missions,” said Thomas Schildknecht, a professor of astronomy at the University of Bern in Switzerland and the director of the Zimmerwald Observatory. “But the risk is increasing, and if we don’t pay attention, then in 10 years from now we’ll be at the level where we can’t do anything.”
Schildknecht’s team has been tracking the most dangerous pieces of space debris for several years and now uses lasers to track their trajectories. As well as predicting dangerous collisions, astronomers use their database to schedule observations when their view won’t be disrupted by stray space junk.
“We get precise information so we can inform astronomers when there is something flying by, so they can choose their observing times a little differently,” he said. “It’s already a problem.”
Schildknecht’s database is one of the sources consulted by commercial space firms like COMSPOC, a Pennsylvania-based company that, among other things, offers to keep satellite operators apprised about any threats in their orbits, including space debris, so they can avoid them if possible.
The company’s chief scientist, Dan Oltrogge, said he welcomes the FCC’s new five-year lifetime and thinks it could be even stricter.
He noted that the rule won’t affect new constellations like Starlink from Elon Musk’s SpaceX — a network of thousands of satellites to provide internet almost anywhere on the globe — because those satellites are already in a low orbit and are expected to deorbit after about a year.
“They’re demonstrating that not only should you do it in five years, you should do way better than that,” he said.
Many experts think the only solution to the space junk problem will be to send up robot spacecraft to gather it all and deorbit it for good.
The Japanese startup Astroscale captured a simulated piece of space junk in a test last year and has a deal with the satellite constellation operator OneWeb to deorbit its satellites.
In 2019, the European Space Agency selected the private company ClearSpace to remove objects from orbit using a robot spacecraft with large claws. Tests are expected to start in orbit in 2026.
And the Seattle-based startup Starfish Space is developing a space-tug called Otter to service satellites in orbit and push space debris into low orbits where it will fall to Earth. The company expects to launch by 2024.
Such active measures are also a key part of a bill for an ORBITS Act that would require NASA and the space industry to explore new solutions to the problems of space junk.
Purdue’s Frueh suggested another solution to the problems of space debris will be to not leave junk in orbit to begin with.
“Moving in the direction of active removal is certainly what we need,” she said. “But it will not be a standalone measure. … We also need to design our missions with space debris problems in mind, and to bring things down as soon as possible after a mission is completed.”