This week, farmers found large chunks of metal from a SpaceX Crew-1 Trunk in a remote paddock in rural Australia. While not an everyday occurrence, the return of rocket bodies (parts of space debris returning to Earth) is a trend that is likely to increase.
dr. Brad Tucker, an astrophysicist and cosmologist at the Australian National University’s Mt Stromlo Observatory, went to check it out. He found that the pieces of rocket debris were 3 meters long and weighed 20-30 kg each.
While it sounds like a cool thing to tell your grandkids, it points to a bigger problem: space junk.
What is space junk and why is it a problemyou?
The term space junk refers to machines or debris left by humans in space and can be anything from dead satellites to paint stains.
Most space debris orbits the Earth or is burned in the atmosphere. But it travels at extremely high speeds (about 15,700 mph in low Earth orbit), so even a small piece can hit spacecraft and wreak havoc.
According to NASA, there are about 23,000 pieces of debris bigger than a softball in orbit. The sensors of the Department of Defense’s global Space Surveillance Network (SSN) track more than 27,000 pieces of orbital debris.
And it’s not just a problem of old space engineering debris from decades ago.
in 2020, more than 60% from launches to low Earth orbit resulted in abandoned rocket bodies in orbit. Worse, 24,000 satellites (and swimming robots) will be launched in the next 10 years, opening up the potential for even more space junk.
With space real estate increasingly overrun with clutter, it can be difficult to precisely position satellites. It also creates a collision hazard for spaceplanes and satellites. Just a speck of paint traveling at 17,000 miles per hour can cause catastrophic damage to a satellite.
Imagine a world without operational satellites. Weather tracking, live event broadcasts, stock market analysis and ATMs would grind to a halt.
And according to researchers, the space debris that survives the heat of atmospheric reentry in the form of debris is potentially deadly. It even poses serious risks on land, at sea and for aircraft.
The risk of being hit increases
Canadian academics recently published Research in Natural Astronomy predicting a 10% chance of one or more casualties from flying debris hitting a person (or infrastructure leading to injury) over a decade. The researchers note that small missiles colliding with an aircraft can cause hundreds of casualties.
For example, in 2016, SpaceX left the second stage of a rocket in orbit. It reintroduced about Indonesia a month later, with two refrigerator-sized fuel tanks reaching the ground intact. Fortunately, it didn’t hit any homes, animals or people.
Where are the space police when you need them?
Internationally there is no clearar and generally accepted casualty risk threshold for falling space debris. NASA programs assess the acceptable risk from human casualties to a chance of less than one in 10,000.
But what makes it worse is that your location increases your risk.
The Canadian researchers found that the latitudes of Jakarta, Dhaka, Mexico City, Bogotá and Lagos are at least three times more likely than those of Washington, DC, New York, Beijing and Moscow to reenter a rocket body.
But has anyone been hit by space debris?
In 1997 Lottie Williams was hit by a flaming ball of space debris shooting through the air in Oklahoma. Fortunately she was unharmed.
But space junk has the potential to land on power lines, cars, trains, farm machinery or in crowded spaces.
Get to know space technology
Tracing space debris has become an industry in its own right. Apple co-founder Steve Wozniak, is president of one company in the industry: the recently launched hijacker.
Earlier this year, it released a space tracking app called “Wayfinder”. It visualizes and tracks satellites and space debris in orbit based on data from the US Space Command, Planet Labs, JSC Vimpel (Russia) and SeeSat-L.
It is useful for space fans as well as researchers and lobbyists who want to act for a response to the problem of space debris.
So how do we deal with this monumental problem? The Canadian researchers argue that governments with populations most at risk from space debris should demand mandatory controlled return of missiles, with significant consequences for non-compliance.
Somehow I feel like we’re still a long way from this kind of action, but I suspect the problem will soon become too big for governments to ignore.