The Catastrophic Risk of Space Junk

Decades ago, scientists warned about the cascading risk of space collisions. Now, Musk is making it much worse—and Trump is eliminating the tracking capability that could help avoid those disasters.

Satellites and space debris. Interactive image: AstriaGraph, U-T Austin.

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Right now, high above you, there are more than 170 million pieces of space debris orbiting around Earth. The overwhelming majority are invisible to us. Most fragments are smaller than a pebble, but there are tens of thousands that are big enough to be actively tracked back on Earth. The largest, a defunct upper stage from a Russian Zenit rocket, weighs 10 tons and is 36 feet long—roughly the size of a bus.

The pieces of space debris in Low Earth Orbit—the bit of space that’s less than 2,000 kilometers (1,242 miles) above Earth—are zipping around the planet at roughly 17,000 miles per hour. At that speed, anything bigger than the size of a pea could destroy a satellite, or potentially even cause the catastrophic obliteration of the International Space Station.

In 1978, an American astrophysicist named Donald Kessler wrote a research paper that prophesized a looming danger if humanity continued to launch more and more objects into the increasingly crowded space around the planet.

“As the number of artificial satellites in earth orbit increases, the probability of collisions between satellites also increases. Satellite collisions would produce orbiting fragments, each of which would increase the probability of further collisions, leading to the growth of a belt of debris around the earth.”

In other words, any collision would create countless fragments—and each of those fragments would drastically increase the risk of further collisions. If a tipping point were reached, there could be an exponential growth of space debris.

In a truly disturbing theoretical worst case scenario, billions of pieces of space debris would make it functionally impossible to safely launch anything into space, wiping out space technology—and potentially trapping humans on Earth forever.¹

This potential chain reaction, which could make nearby space unusable for humanity, is known as Kessler Syndrome. And it would be debilitating for modern industries that rely on satellites, including navigation, weather forecasting, emergency response, energy grids, banking and financial transactions, broadcasting, and the Internet of Things.

Writing in 1978, Kessler warned that such a tipping point could arrive within three or four decades. That hasn’t happened—yet—but many scientists believe we are getting closer to that catastrophic point of no return.

In 2009, two satellites collided—a defunct Russian satellite called Kosmos 2251 and another called Iridium 33. They were each traveling at 26,000 miles per hour. The collision produced thousands of pieces of debris, including one piece that, in March 2012, came within 390 feet of hitting the International Space Station.

The risks are made even worse by reckless behavior by Elon Musk’s company, Starlink, and by authoritarian state actors—with an enormous surge in the number of objects being launched into space during the last five years.

Consider, for example, the chart below from the European Space Agency’s report released in April, which shows the total area of objects being launched into space. The spike since 2020 is a radical departure from preceding years.

Area of human made space objects in all orbits around Earth. Image: ESA.

Thankfully, the United States government invested in a tracking system that could be used to effectively avoid satellite collisions. Think of it like a one-stop Air Traffic Control, but for space. And it’s a bargain, too: it costs only about $50 million a year, which is 0.00074 percent of the US government budget. A no-brainer.

Since it’s obviously a good idea, the Trump administration has proposed a budget that will eliminate the satellite and space debris tracking capability, thereby amplifying the risk of catastrophic collisions. Without it, Kessler Syndrome could eventually lurch from scientific theory to grim impending reality.

In this edition, we’ll explore why the space junk problem has gotten much worse in recent years; how China’s and Russia’s reckless behavior is exacerbating an already crowded orbit; why space weapons complicate the picture; how Elon Musk’s company is ramping up debris risks and damaging the ozone layer in the process; and most intriguingly of all, how humanity might soon begin to launch sci-fi marvels—from nets and harpoons to lasers—that can eliminate or move space junk out of Earth’s orbit.