Houston, we have a space junk problem

It seems humans can't help but to leave traces of themselves everywhere they go. That includes space, where rocket parts and decommissioned satellites litter the low orbit around Earth. It's called space debris — or, more casually, space junk — and as more of it accumulates, the greater the danger of it colliding with other spacecrafts or satellites becomes.

Plans to clean up the space junk have included trapping it, pushing it out of orbit, and slingshotting it into Earth’s atmosphere, where it would burn up. But a recently published report by economists with the University of Colorado and Middlebury College claims that this won't stop people from creating more debris. Their novel solution is an international agreement to hit countries and companies who launch things into space with expensive fees and fines.

What's with all the space junk

Space junk is made up of whatever satellites, equipment, and rocket parts humans have abandoned as we explore and utilize the space around the Earth. It can be as large as a solar panel or as small as a bolt used to screw it down.

Humans have been exploring space since the Sputnik days, starting in 1957, and that means there's at least six decades' worth of trash out there. There's debris on Mercury, Venus, and an estimated 20 tons that were left behind on the moon when Apollo astronauts had to abandon equipment they didn't need. According to NASA, there are at least 20,000 pieces of space junk floating around in our planet's low orbit that are larger than a softball. There are 500,000 more pieces smaller than the size of a marble, and possibly millions of pieces too small to track.

Depending on how far up these pieces are, it can take anywhere from years to centuries for them to drift into the Earth’s atmosphere, where they usually burn up before they hit the ground.

A risk to equipment, astronauts, and Earthlings

With all that junk floating around, collisions with and between debris is becoming an increasing concern within the space industry. Despite how peaceful floating in space appears to be in movies, the orbiting junk is actually traveling at very high speeds up to 18,000 miles per hour, which is "almost seven times faster than a bullet," according to NASA. At that speed, even a flake of paint can chip a window on the International Space Station like a pebble hitting the windshield of a car on the highway.

"An object up to 1 cm in size could disable an instrument or a critical flight system on a satellite," stated the European Space Agency in a press release. "Anything above 1 cm could penetrate the shields of the Station's crew modules, and anything larger than 10 cm could shatter a satellite or spacecraft into pieces."

This makes it that much harder for manned and unmanned spacecraft to go into space. "Micrometeoroids and orbital debris (MMOD) is the number one risk for NASA's human spaceflight programs," NASA reported in 2016. ('Orbital debris' is another name for space junk.) And it's not just astronauts who are put at risk while in space; the junk can collide with equipment that is currently in use, such as weather satellites and SpaceX's privately owned satellites.

Researchers believe the space junk problem will only get worse. Back in 1978, NASA scientist Donald Kessler predicted a scenario where the collisions between space junk would create more space junk that could shatter into even smaller pieces. He theorized that this chain reaction, named the 'Kessler syndrome,' would create a hazardous environment around Earth's low orbit and make space missions and satellite launches more dangerous to maneuver.

Furthermore, there's a slight risk of falling debris causing damage to people on Earth. It's a very low risk, to be fair, since most debris re-entering the atmosphere tends to burn up before hitting the ground. But the chances are there: In 1997, one woman in Oklahoma was tapped on the shoulder by a small piece of a rocket. In China, where the nation's space program continues to expand, rural villagers have reported chunks of spacecraft landing on homes after rocket launches.

Decluttering space with hard-hitting fees

Engineers have been hard at work trying to figure out how best to clean up space debris. Japan's space agency, JAXA, has been toying with the idea of using an electrified line to knock space debris into the atmosphere like a whip. Other scientists and engineers have drafted up different proposals in the hopes of beginning a cleanup process sometime in 2025.

But the economists behind this recent study believe these solutions won’t stop nations and corporations from freely abandoning more objects in space. To fix that mentality, the study's authors say 'orbital use fees' could make people think about the costs of littering while adding value to that precious space around the planet.

These fees, according to a statement from the University of Colorado at Boulder, could be "straight-up fees or tradable permits" that basically charge people for "current and future costs of additional collision risk and space debris production." In other words, it's almost like a carbon tax for space pollution. The fees may vary depending on how high the risk of collision is in a particular orbital area.

The proposal's goal is to force space agencies and private companies to think deeply about the "lifetime value" of their satellites versus the cost of increasing the risk of collision in space. Fees would increase as the years go by, ideally reaching around $235,000 per satellite per year by 2040.

The researchers note, however, that this type of plan would only work if all nations and private entities with satellite-launching capabilities agree to it.

"[That's] about a dozen that launch satellites [...] and more than 30 that own satellites," stated the University of Colorado release. "In addition, each country would need to charge the same fee per unit of collision risk for each satellite that goes into orbit, although each country could collect revenue separately."

Convincing everyone to agree to the plan might be tricky, but the economists believe it's necessary to think of these things while space exploration remains fairly young. Otherwise, we could be facing the possibility of conflict over space junk as the problem spirals out of control.