In the U.S., the average person produces 4.9 pounds of trash a day. Multiply that by a population that has been steadily increasing for centuries, and the amount of garbage circulating within our planet quickly reaches astronomical proportions. A sunset stroll on many beaches around the world accompanied by the sound of crunching microplastics underfoot will reveal just how adept humans are at finding ways to dispose of their waste.
The trash problem here on Earth is at crisis proportions, and as we continue to expand our presence in the solar system, we're bringing our trash problem with us, threatening to bleed out far past the Earth’s atmosphere. Since space exploration began in the 1950s, countries have deployed thousands of satellites, rockets and spacecraft. Remnants of this machinery get left behind in orbit. Known simply as space junk, which is estimated to exist on the scale of millions of tiny and not-so-tiny objects in the Earth’s atmosphere and beyond.
That might not seem like a lot, relatively — after all, the solar system is bigger than any of us can wrap our heads around — but collisions among even fragments of space junk have the potential to cause catastrophic damage. As explained by a phenomenon in physics known as Kepler’s law, a single collision among space debris has the potential to set off endless additional collisions like a set of dominoes. This could trigger a severe problem known as Kessler syndrome, in which there could be so many chaotic colliding objects in orbit that it would wipe out many communications networks and could even render space travel impossible, essentially grounding humans on Earth indefinitely.
Thankfully, Kessler syndrome remains theoretical for now, but space junk collisions have already caused the destruction of a Chinese satellite in 2021 and a U.S. satellite in 2001. And the International Space Station (ISS) has had to fire off thrusters to move from the path of spiraling space junk twice this year. In fact, the ISS may one day itself become space junk.
As more and more satellites and other objects are launched into space, there has been a growing movement to ensure that the things orbiting our planet are properly disposed of. So where does a satellite go to die?
When a satellite nears the end of its life, it is either sent outward to the “graveyard orbit,” past the geosynchronous region where most satellites orbit, or brought back down to Earth in a region known as the “satellite graveyard.” The idea is to not leave satellites just hanging around in space, said Carolin Frueh, Ph.D., an associate professor of aeronautics and astronautics at Purdue University.
Once an object ends its mission, it has five years to be disposed of.
“One of the problems, for example, is that the rockets if they stay in orbit, tend to be involved frequently in fragmentation events, either because they might spontaneously explode or they're hit by something and then explode because of remnant fuel,” Frueh told Salon in a phone interview.
Once an object ends its mission, it has five years to be disposed of, said Patrick Seitzer, Ph.D., a professor emeritus of astronomy at the University of Michigan.
“You’re supposed to boost it 300 kilometers into a graveyard orbit and then totally passivate it, meaning you drain all the fuel, discharge the batteries and cut the charging circuit so the spacecraft doesn't come back as a zombie spacecraft decades later,” Seitzer told Salon in a phone interview.
Larger objects like the ISS are guided back down to Earth through a controlled re-entry procedure. Several hundred spacecraft remnants have fallen into this area of the ocean since the space junk issue arrived on the space agency’s radar in the 1980s, Seitzer said. Through this process, anything roughly two tons or less will burn up in the atmosphere and not make it to land — although this depends on the object's compostiion — but objects larger than that will fragment on their way down, Frueh said. Those pieces will then rain from the sky in the most remote corner of the Pacific Ocean, 3,000 miles from New Zealand and 2,000 miles north of Antarctica.
“There is nothing there, [besides] a few islands and very few fishermen,” said David Whitehouse, Ph.D., an astronomer and author who has written about the satellite graveyard. “It’s absolutely in the middle of nowhere.”
Also known as the “pole of inaccessibility,” or Point Nemo, this region is about four kilometers deep and home to sea cucumbers, coral branches and sea urchins, said Autun Purser, Ph.D., an oceanographer at the Alfred-Wegener-Institut in Germany. However, due to having very low flow conditions, marine life is relatively quiet in the area. Most of the seafloor in the region is made up of soft mud, so metal scraps or hard bits from any decommissioned satellites rust and fall apart over time if they’re not slowly buried, Purser said.
“If there are chemicals or radioactive materials, these could well be hazardous, but for most satellite falls, the impact is probably quite small,” Purser told Salon in an email.
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NASA made plans to put the ISS, which is the size of a football field, to rest in the Pacific Ocean in 2031, following a call to action from other space agencies. The European Space Agency (ESA) is also working to reel in the largest satellite in orbit, Envisat, after it lost contact with the control team on Earth in 2012.
“There are also missions underway for active debris removal, where you go up and you snare and grab onto a piece of debris and do a controlled reentry into the Earth's atmosphere,” Seitzer said.
In February of this year, the Federal Communications Commission (FCC) established the Space Bureau to better regulate a fast-growing satellite industry. Last week, the agency issued its first fine to Dish, charging the company $150,000 for failing to deorbit an old satellite in accordance with its policy. In the same month, U.S. Senators introduced the ORBITS Act to set up infrastructure to manage growing loads of space junk.
As Sen. John Hickenlooper from Colorado, one of the leaders to introduce the bill, said: “Because of the threats from debris already in orbit, simply preventing more debris in the future is not enough.”
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Yet while it’s necessary to throw away our space trash responsibly, it’s also important to consider the environmental impact that these objects have when they burn up through the atmosphere on the way down, Frueh said. “One of our concerns is actually the environmental impact on the atmosphere that is created in the process when those materials have burned up or partly burned up,” she said.
The Space Surveillance Network is currently tracking 50,000 objects orbiting Earth but that could increase to some 400,000 satellites if private companies like SpaceX and Amazon continue launching new ones in the coming years, Seitzer said. Just like on Earth, junk, debris and larger remnants of machinery in space have to go somewhere.
“The unknown composition of some satellites might be worrying, but it is definitely better for the more basic, ‘big metal lumps’ to land here than hit land at speed, where they may cause damage,” Purser said. “Trash is never ‘nice,’ but if it has to go somewhere, here is probably a good choice.
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