With plastic pollution overwhelming our oceans, particle pollution threatening the air we breathe, and our carbon dioxide output changing our climate, society should be taking an important lesson as we move into our next frontier in space. We should be taking control of our waste output from the start, instead of rushing to clean up the damage after it’s already done. But in the decades since we’ve started making forays into space, that lesson hasn’t yet taken hold. Currently, NASA says there are 170 million pieces of debris orbiting our planet, including around 20,000 larger than a softball and another half million the size of a marble or larger.
The recent uncontrolled reentry of China’s Tiangong-1 spacelab was an attention-grabbing example what happens when humans abandon space efforts, but didn’t really represent the broader problem of smaller, but more numerous, pieces of space debris. This can include spent rockets, fragments from collisions and dilapidation, and old satellites that have broken apart. But in space, these smaller pieces of junk can prove much more dangerous than the Tiangong reentry ultimately did. Stray flecks of paint, in high velocity orbit, have cracked the windshield of the space shuttle more than once. At least twice every year, the International Space Station is forced to steer itself out of the way of debris.
At average speeds of 10 kilometers per second (22,000 mph), a one-centimeter fleck of paint can inflict as much damage as a 550-pound object moving 60 miles per hour on Earth. A 10-centimeter object would have an impact comparable to 7 kilograms of TNT, according to NASA.
The more this space junk builds up, the more serious the risks. Kessler Syndrome, named for astrophysicist Donald Kessler who first suggested the problem, refers to the potential for a chain reaction when collisions of debris in orbit create more debris in turn. Once the amount of debris in a particular orbit has reached a critical mass, such an event could cause a cascade of collisions, ultimately leading to the orbit becoming entirely unusable. In the 1970s, Kessler suggested such a critical mass was three to four decades away, and today some scientists say that point has already been reached in low-Earth orbit, between 560 and 620 miles (900 to 1,000 kilometers) up.
About 4,000 active and inactive satellites are orbiting Earth currently, according to some estimates.
Jason Held is chief of Saber Astronautics in Sydney, a company working towards technology that can remove debris from orbit. According to Held:
“If you think of the early days of aviation you didn’t need air traffic control. It took a few plane accidents before air traffic control was put in place…People are now starting to see congestion up in space, and if a satellite is up there and it deactivates for some reason while up there and you can’t move it, you have a giant bullet flying around at 8 kilometers per second.”
Held’s company is working on a device called the DragEN, that will attach to spacecraft and satellites, weighing less than 100 grams, able to release hundreds of meters of conductive string that can draw electric and magnetic forces as it makes its way through Earth’s magnetic field. It then uses this force to draw the object back into the planet’s atmosphere, where it then combusts. This process can take decades without intervention.
Other innovators are also working toward high-tech solutions to the space junk problem. Professor Craig Smith, chief executive and technical director of the Australian aerospace technology company Electro Optic Systems, is working with researchers to create a high-power laser to push debris out of the path of a collision.
According to Smith:
“If some of the satellites were to go offline, it could take a long time to get a replacement up, and many businesses, like the telecommunications industry, are dependent on them. It’s a serious issue. We have oceans and rivers, and we pollute them until they become almost unusable. We’ve done exactly the same with space. We’ve left junk everywhere.”
The hope is that the laser could eventually destroy debris completely.
Earlier this month, an experiment called RemoveDebris launched with the SpaceX Falcon 9 Rocket, on its way to the International Space Station. There, astronauts will test technologies, such as a robotic arm, a net, a small harpoon, and a large membrane, to increase drag and pull debris back to Earth. The project is being led by the University of Surrey’s Space Center.
As promising as some of these innovative solutions may be, it is time to start planning from the beginning on how to avoid leaving objects behind in space. As more nations begin activities in space, it is crucial not to assume that debris left behind won’t pose a problem. On top of science and exploration, Earth’s orbit has become an increasingly vital component of the world’s economy, and it’s essential to ensure smooth operations there. Activities in space today need to take the future into account – something we have all too often failed to do on Earth.