The Pacific Ocean is home to two monstrous, swirling vortices of human junk. Tangled fishing nets, garbage bags and millions of tiny pieces of plastic twirl in the waves east of Japan and sway in the current along the California coast. The kipple at opposite ends of the Pacific is connected by a stream of debris, weaving its way across the world’s largest ocean.
The disjointed mass of waste is known as the Great Pacific Garbage Patch.
It’s often portrayed as a floating island of trash, an artificial landmass cobbled together by an ever-increasing amount of discarded single-use plastic. But it’s not Coke bottles, scissor packaging and six-pack rings that make up the majority of its junk. Almost half of the garbage comes from fishing equipment used on commercial vessels. Abandoned netting and gear, lost or discarded at sea, form large clots that circulate in the Patch for years.
Something similar is happening overhead, between us and the stars.
At the edge of the atmosphere, ensnared by the Earth’s gravity, are masses of metal we’ve been sending into orbit since 1957. Satellites, as big as a bus and as small as a toaster, enable global communication, predict the weather and map the surface of the planet. They’ve become an essential component of our daily lives. Telecom satellites help us Zoom with friends across the globe, GPS prevents us from getting lost in an unfamiliar city, and environmental satellites provide us with a weekly forecast.
But they aren’t immortal. Eventually, they stop working.
After death, they continue their orbits alongside the rockets that put them there. The harshness of space also sees them slowly weaken. Smaller debris gets chipped off, worn down or scraped away. We’ve been filling space with junk for the last six decades, building a Great Garbage Shell.
Its existence threatens newly launched satellites and rockets and poses trouble for spacecraft already in orbit, like the International Space Station, and the systems that we depend on for our daily activities on Earth. “Space debris is extremely dangerous,” says Rebecca Allen, an astrophysicist with the Swinburne Center for Astrophysics and Supercomputing in Melbourne, Australia. “Something the size of a ChapStick could punch right through the space station.”
Since the early 1970s, researchers have explored how troublesome this leftover junk might become. The envelope of cosmic jetsam, an assortment of potentially millions of tiny objects, is now being studied more intently than ever before.
We may have gravely underestimated the problem.
It’s impossible to pinpoint when the very first piece of plastic waste tumbled its way into the ocean. But we know exactly when space morphed from unspoiled void to planetary dump.
In October 1957, the Soviet Union launched Sputnik 1, a reflective orb with four long, metal tendrils. It was the first human-made object to orbit the Earth — a milestone in the burgeoning space race between the US and the Soviet Union. In January 1958, it reentered the atmosphere and burned up. By the time humans landed on the moon in July 1969, hundreds of satellites had been sent to space.
The number of live satellites currently orbiting the Earth stands at almost 2,800, according to a database maintained by the Union of Concerned Scientists. Almost three times that amount are defunct. The junk has been building up.
“As we’ve launched more and more satellites into space, the problem has gotten progressively worse,” says James Blake, an astrophysicist Ph.D. student at the University of Warwick studying orbital debris.
Cluttering orbit with satellites is a problem long recognized by astrophysicists. Donald Kessler, NASA’s famed orbital debris researcher, was acutely aware of the problems space junk could pose for access to space. In 1978, he theorized a doomsday scenario in which low-Earth orbit, or LEO, where the ISS does its laps, would become so polluted with junk it could cage humankind inside the planet’s atmosphere.
His theory is straightforward. The probability of satellite collisions increases as more satellites are launched. Collisions produce a spattering of orbital fragments, increasing the probability of further collisions. This produces more fragments, increasing the risk of collision. And so on. Kessler reasoned that a string of collisions, over many years, might result in a runaway process generating endless debris that would envelope the Earth. Kessler predicted the number of satellites could reach this point by 2020.
His doomsday scenario hasn’t yet come to pass, but space has become exponentially busier. Companies that use reusable rocket stages to ferry satellites to orbit, like Elon Musk’s SpaceX and Jeff Bezos‘ Blue Origin, have reduced the cost of launch by a factor of four. Satellites have been miniaturized to the size of a shoebox, with improvements in manufacturing and technology making them far cheaper to produce.
When they go up, they’re tracked from the ground; orbits are precisely calculated by organizations like the United States Space Surveillance Network, or SSN. What isn’t as closely tracked is the material shed from rockets or payloads during launch, millions of tiny fragments generated by spacecraft being worn down by the harshness of space or the metallic fireworks created by an in-orbit explosion of leftover fuel or batteries.
It’s these untracked and unseen pieces of junk that pose the biggest danger.
On Oct. 13, California-based space debris tracking service LeoLabs sent up an alarm: Two large objects were on a collision course 615 miles above the coast of Antarctica.
One was a defunct, barrel-shaped Soviet satellite with a 17-meter-long boom, launched in 1989. The other was a spent rocket stage, launched by China 20 years later. According to LeoLabs, there was a one-in-10 chance the two objects would collide. Traveling at almost 10 miles per second, the collision would have generated a fountain of debris, throwing pieces of smashed satellite into bizarre orbits that crisscross with other objects in space.
“Luckily, it missed,” says Daniel Ceperley, CEO and co-founder of LeoLabs. “If it had hit, there could have been 25% more debris in an instant.”
The episode is emblematic of the traffic in LEO, at the fringe of Earth’s atmosphere. In the past five years, the amount of objects in this region has risen sharply. According to databases maintained by the European Space Agency and the SSN, there are around 25,000 objects in orbit. Of these, 55% reside in LEO, at altitudes lower than 1,240 miles.
And the problem is set to get worse.
In the next three to five years, giant constellations containing thousands of satellites are expected to be placed into orbit. Organizations like SpaceX, as well as e-commerce giant Amazon and telecommunications company OneWeb, have all proposed their own mega-constellations for LEO. If they succeed, the amount of satellites could increase by as much as 600%, fundamentally changing the space environment.
“Such a large injection into orbit will place a huge amount of strain on our current monitoring capabilities,” Blake says.
SpaceX didn’t respond to a request for comment.
Today’s space object databases are comprehensive, but they’re not complete. Private companies, like LeoLabs, work adjacent to the SSN, Space Force’s Space Fence and other researchers to map the orbital environment. But space is big and dark. Satellites are one thing, but statistical models provide almost unfathomable estimates for small chunks of junk: There are 900,000 pieces of debris smaller than 10 centimeters and over 128 million pieces less than 1 centimeter enshrouding the Earth, according to the most recent estimate by the ESA’s Space Debris Office.
Speeding around the Earth at over 17,000 miles per hour, these scraps become stray bullets. They can perforate, chip or ding bigger spacecraft. And they’re so small that detection and tracking is nearly impossible.
It’s not just LEO where the problem lies, either. Blake is a member of DebrisWatch, a collaboration between the University of Warwick and the UK’s Defence Science and Technology Laboratory to find and catalog space junk. He recently led a study, published in Advances in Space Research in October, attempting to locate small pieces of debris in geosynchronous orbit, or GEO, 36,000 kilometers above the Earth, where important satellites, like those used to monitor the weather, are stationed. Satellites here remain in lockstep with the Earth, orbiting the planet at the same speed it rotates.
His team found 129 faint objects in GEO, previously unseen, that could pose harm to satellites stationed there.
“Until we’re able to monitor and catalog all the dangerous debris that pose a risk to active satellites, we need to do more,” Blake says. He notes that inroads are being made by space agencies and commercial companies, but fusing and sharing all of the data into a single coherent catalog is a significant hurdle.
“Once you have the tracking, then I think you’re gonna see a lot more money go into debris management and mitigation,” Allen says.
I was a teenager once, so I can tell you this: Making a mess is easy, but cleaning up is difficult.
When it comes to the planet, you only need to look at the Great Pacific Garbage Patch to understand how hard it can be. For seven years, Dutch environmental nonprofit Ocean Cleanup has iterated and reiterated its own technological solution to the plastics pollution problem. But it was only in October 2019 that the organization’s plastics-catching device began pulling bottle caps and nets from the sea.
Space could be even harder to sweep.
In GEO, defunct satellites either have to be serviced and maintained or buried in a higher orbit, known as a “graveyard” orbit, where their potential for collision is drastically reduced. In LEO, things are even more problematic: Many of the 900-plus rocket bodies tracked by LeoLabs were launched in the ’80s, for instance, and they’re still up there.
Companies are getting better at creating rocket bodies and satellites designed to fall back to Earth, but there’s already a lot of junk up there doing nothing but clog up the space highway. “The one thing we need to do is start steadily pulling some satellites and some of the large debris out of space,” Ceperley says. “It needs to become a routine part of the industry, but it’s not there yet.”
There are currently no debris removal methods, though a handful are in development. In 2018, Surrey Satellite Technology in the UK showed off its space net, which ensnared a piece of debris with a Spider-Man-like web. A few months later, it demoed another technology — the RemoveDebris space harpoon.
The Japanese Space Agency, or JAXA, in collaboration with space sustainability startup Astroscale, plans to trial another method. In 2023, the duo will launch a spacecraft that can drag a spent rocket body toward the atmosphere, taking it out of orbit. The ESA tapped Swiss space tech startup ClearSpace for its own debris removal mission to launch a craft that will chase and grapple with an old payload adapter.
These missions focus on large debris, like rocket bodies, but removing small debris presents an even bigger challenge, according to Allen. Technical advances in tracking, like those envisaged by Ceperley’s LeoLabs, will allow smaller pieces to be tracked, but actively taking them out of orbit? “Nobody’s got a good technical solution for the little stuff,” he says.
Space is often referred to as being the common heritage of all humankind — everyone should have equal access and benefits from its use. Who is responsible for decluttering orbit? That’s a tricky question.
There are five treaties addressing space and space-related activities. None directly speak to the problem of space junk. The United Nations Committee on the Peaceful Uses of Outer Space has set a number of space debris mitigation guidelines, but countries aren’t bound by them, leaving each nation to develop its own strategies.
Many spacefaring nations and organizations, like the US, Russia, Japan and the ESA, have developed their own procedures to keep space sustainable. In the US, NASA is hoping to establish the Office of Space Commerce as the overarching agency to handle management of space traffic. It’s currently handled by the Department of Defense.
There’s also the Inter-Agency Space Debris Coordination Committee, which includes 13 member space agencies and coordinates activities relating to research and studying space debris around the world. “Adherence to the guidelines is far from universal,” Blake notes. Facilitating a more transparent, open sharing of space traffic management will enable more robust methods for dealing with junk but regulatory action is lacking.
“We’re coming into this time where we’ve got to think about regulating space,” Allen says. “And it’s not just about treaties and agreements.” Similarly, Ceperley, from LeoLabs, notes private companies in the space industry are looking for “regulatory certainty” as they invest heavily in expensive assets they need to track and maintain for, potentially, decades.
As it stands, Ceperley says, regulators “focus on the prelaunch licensing and documentation.” Once you get signed off for launch, nobody is chasing you about where your satellite is or where it’s going to end up. As a counter, he highlights New Zealand’s space agency. The agency uses his team’s tracking platform to follow everything launched from the country and assess if it’s operating according to plan. That information, he says, feeds back into policy.
There’s also a more capitalistic revolution that is yet to take place: Cleaning up orbit costs money. You could regulate the types of spacecraft and satellites being launched and ensure they adhere to strict orbital parameters, but there’s still junk circling the Earth above your head right now that isn’t coming down without assistance.
“Actually putting some hard-headed numbers against it, hopefully, we’ll be able to jumpstart that industry,” Ceperley says.
Visualizations of the space debris problem are striking. Tiny, satellite-shaped icons flitter across the screen, sped up to highlight the immense masses of metal moving around Earth at any one time. Staring at this Great Garbage Shell, it’s impossible not to think of the Pacific, clogged with plastic.
When bottle caps and fluorescent detritus were discovered in the stomachs of sea birds in the late 1960s, the public began to take a keen interest in our plastics problem. It was a moment of realization; we were awake to the unintended consequences of our actions. We still consume single-use plastics with reckless abandon; turtles still wash up on shore, their shells squeezed into the shape of an hourglass by milk rings discarded years ago. We were too slow to act.
We’re on the cusp of a similar moment in space. Collisions will become more commonplace. Debris will become more plentiful and potentially more damaging. The numbers bear it out: A catastrophic collision is inevitable.
In September, the International Space Station maneuvered its way out of a potential collision with an unspecified piece of space debris. The crew shambled into the Soyuz capsule docked at the station — a safety procedure designed to get them back to Earth should a catastrophic collision occur. It was the third time this year they made such a maneuver.
Fortunately, the debris passed safely by. Will we be able to say the same next time?