Brad Plumer

Space is getting awfully messy. The amount of debris in Earth’s orbit keeps multiplying each year, damaging satellites and putting astronauts in harm’s way. If the problem gets severe enough, it could eventually make low-earth orbit unusable.

Scientists have known about the space trash problem since the 1970s. Humans have placed thousands of objects into orbit since Sputnik, and some of those old satellites and ejected rockets are breaking apart.

As pieces collide with each other at high speeds and shatter, they create more debris, repeating until space is saturated with high-flying junk.

Despite ample warning, the world’s nations have never quite been able to agree how to solve the problem. The technology to clean up the debris exists, but no one can decide how to fund the process.

So that’s where economists come in.

In a recent paper, three economists argue that orbital debris is a standard “tragedy of the commons” problem. Space is a precious resource, and people overuse it, since no one pays the price for waste created by satellites.

Similarly, no one person has incentive to clean up the mess themselves. Economists typically solve this problem with what’s known as a Pigouvian tax. Why not place a user fee on all orbital launches to pay for clean-up?

“User fees are a solution straight out of the Reagan era to deal with these environmental issues,” says Peter Alexander, an economist at the Federal Communications Commission and co-author of the paper. (He helped write the paper in his spare time, not on behalf of the U.S. government.) “This is a classic commons problem.”

The orbits around Earth are undeniably valuable. Satellites are used for everything from communications to television to Earth monitoring and military surveillance. Roughly 49 percent of satellites are in low-earth orbit, which is also where astronauts work. Another 41 percent are higher up, in geosynchronous orbit.

Yet those orbits are getting clogged with all the stuff humans have placed into orbit, including bits of satellites that have cracked apart or old upper-launch vehicle stages:

The U.S. Strategic Command is aware of more than 21,000 man-made objects in orbit larger than 10 centimeters. But there are hundreds of thousands of even smaller pieces circling the Earth that can’t be tracked. Many of them are moving at extremely high speeds, some as fast as 22,000 mph.

The nightmare scenario is a cascade of collisions that becomes unstoppable. Metal shards would start destroying satellites, which would create even more debris, until low-earth orbit became unusable.

Here’s the good news, though.

Scientists have come up with clever schemes to mop up the orbital debris. We may be able to shove the really troublesome chunks into “graveyard orbit,” 22,000 miles away from the Earth.

Recently, aerospace engineers at the University of Colorado outlined a plan to haul away space debris using static electricity.

The problem, however, is that the world’s nations can’t agree on how to pay for these clean-up efforts. Everyone has an incentive to keep launching satellites into space, but no one has any incentive to invest in cleaning up the orbital debris left behind.

So, in their paper, economists Alexander and Brendan Michael Cunningham, along with Nodir Adilov of Indiana University-Purdue University, propose a simple solution.

Countries should impose a basic fee or tax on all orbital launches. “Up until now, we’ve had voluntary guidelines around launches, and the physics community is saying this is not sustainable,” says Alexander.