(Illustrations by Ibrahim Rayintakath)
In 1957, the Soviet Union launched the first satellite, Sputnik. Since then, the space above Earth has been flooded with thousands of satellites, spent rocket stages and the debris from several catastrophic events. As a result, Earth’s lower orbit has been littered with an increasing amount of junk that is careening through space at intense speeds, threatening satellites and even the International Space Station.
Last year, the problem became serious enough to prompt the Biden administration to call for the abolishment of tests that destroy satellites in orbit. The announcement came after Russia blew up a dead satellite in 2021, creating a massive debris field that threatened the ISS astronauts along with other satellites.
In the future, if the international community cannot come up with a way to regulate the Wild West of space, the debris problem will get worse. Every year there are dozens of near-collisions between active satellites or pieces of debris. The more satellites that flood Earth’s orbit, the greater the chances that one will happen. The more collisions, the more debris — all of which fuels what many fear could become a destructive cycle.
Earth’s lower orbit is crowded by a number of objects — including working satellites as well as space debris like defunct satellites, spent rocket stages, and the detritus from missile strikes and collisions.
Working satellites
There are more than 6,000 active satellites rotating around Earth as of Jan. 9, according to LeoLabs, a company that tracks satellites and debris in Earth’s lower orbit. Some are small, the size of a shoebox; others are much larger. Their functions vary widely, from providing television and Internet service, to GPS and weather monitoring.
Defunct satellites
Satellites can’t live forever. They run out of fuel eventually, or malfunction and become giant pieces of garbage whizzing around the Earth. Currently, there are more than 1,800 defunct satellites in lower orbit. Under the current rules, the United States requires satellites to deorbit — or burn up in Earth’s atmosphere — after 25 years. But many think that regulation is far too lax and that satellites should be deorbited earlier.
Fragments
Over the years, astronauts on spacewalks have dropped a camera lens cap, a screwdriver and even a spatula — adding to the curious collection of things in orbit, which includes eroded spacecraft parts and baseball-sized chunks of garbage.
Even small pieces of debris — a nut or even a fleck of paint — can cause enormous damage in space.
Spent rocket stages
As rockets launch to orbit, they often discard upper stages that have their own engines and propellant. If they don’t burn up in the atmosphere or fall back to Earth, they join the cloud of space debris in low Earth orbit. Several of these are the size of a school bus, spinning wildly as they move through space. In total, there are nearly 1,000 spent rocket stages of varying sizes in Earth’s lower orbit.
The United States and private companies like LeoLabs track tens of thousands of pieces of space debris, including operational and non-operational satellites, rocket stages and unknown objects. But there are many more pieces too small to see. NASA estimates that there are roughly 500,000 objects between 1 and 10 centimeters in diameter orbiting Earth, and that there are more than 100 million particles larger than 1 millimeter. (The agency said that as of January last year, the amount of material in orbit was more than 9,000 metric tons.)
And as more companies flood Earth’s orbit with an increasing number of satellites, there is growing concern that collisions — which would only make more debris — are inevitable, as theorized by NASA scientist Donald J. Kessler in 1978.
If nothing is done, space could become so polluted that it is unsafe for human exploration and could leave some of the world’s most sensitive satellites, which are used for GPS and missile warnings, at risk.
Despite the growing amount of launches and space debris, there are very few rules of the road in space. While the Pentagon issues warnings about possible collisions, it cannot order one spacecraft operator to move out of the way.
Thankfully, there are a number of steps governments and companies are taking to curb the problem of space junk. The Biden administration has called for a ban on all destructive antisatellite tests, and recently, the Pentagon launched a program, called Orbital Prime, under the U.S. Space Force that will give companies seed money to develop the technology needed to clean up space.
That includes grappling large bodies and pulling them out of orbit (one company that is working with the European Space Agency proposes using a spacecraft with large arms that would function like a Venus’ flytrap), or refueling or repairing them so they can last longer and maneuver in space.
To track orbital debris, the Pentagon and commercial companies rely on a network of ground-based radar and optical telescopes. Radars can measure the distance to their targets and some can even track more than one object at a time, according to the Secure World Foundation, a think tank. Telescopes collect light reflected by debris and can cover large areas quickly and at high altitudes. The U.S. Space Force says it tracks more than 40,000 objects in space the size of a fist or larger. But there are at least 10 times as many smaller objects in orbit that the Pentagon can’t reliably track.
Ultimately, many space officials say that cleaning up space will require foreign governments to work together.
