MELBOURNE, Fla. – For more than six decades, humans have been launching spacecraft into low-Earth orbit and out into the universe, including satellites that provide GPS and weather forecasting down on Earth, but they have limited lifespans.
After a spacecraft is no longer serving a purpose, it becomes junk.
On a recent episode of “Space Curious,” we talked to experts who know a lot about space junk, and what challenges humans face in cleaning up the messes we make.
Daniel Batcheldor is the former head of aerospace physics and space sciences at Florida Institute of Technology in Melbourne. As an astrophysicist, Batcheldor said when people think of space debris, they might be picturing a scene out of the 2008 Pixar movie “WALL-E.”
“One of the most vivid examples that we have is, at the beginning of the movie ’WALL-E,’ where a spacecraft has to punch through all of this really thick debris in low-Earth orbit and get through that,” Batcheldor said. “And one thing that these, these movies and TV shows fail to, to convey properly is the, the size of space. And so whilst we say ’space debris,’ it’s not like there’s hundreds and hundreds of objects all crammed together or creating a huge problem. Space is big, and the separations between these pieces of space debris are quite large.”
Batcheldor said most space debris, or space junk, is tracked and right now not posing a danger to any new missions.
“We’re very, we’re quite good at tracking where these pieces of debris are, or where the satellites are,” Batcheldor said. “It could be 50, 100, 200, 400, 500, 1,000 years from now, right? But at some point, it’s going to become a problem.”
While space is very big, many spacecraft need to be in the same real estate -- low-Earth orbit -- to provide the services we rely on around the globe. This is the area most concentrated with space debris, according to NASA’s Orbital Debris Program Office.
The Orbital Debris Program Office, at NASA’s Johnson Space Center, leads the development of national and international policies and technology focused on mitigating debris risks. According to the ODPO, there are about 500,000 marble-sized debris objects predicted to be in Earth’s orbit and more than 1 million objects less than 1 milometer or smaller.
To get ahead of the problem, there are standards of practice in the U.S. and among other countries with space programs that determine how long a satellite can be in orbit before it needs to de-orbit.
The United Nations’ Office for Outer Space Affairs is the coordinating body working to prevent the creation of space debris -- and the United States Defense Advanced Research Projects Agency, better known as DARPA, has been leading efforts through international workshops to get a handle on how to coordinate satellite repair and space debris removal.
Private companies and researchers are also developing technology to do something about capturing pieces of space debris to clean up low-Earth orbit, which, as it turns out, is pretty complicated.
Markus Wilde is an assistant professor of aerospace engineering at Florida Tech. His research area of focus is on robotics in space, including satellite repair in space and removal of space debris.
Part of the challenge with space debris removal or plans to refuel satellites in orbit has to do with the nature of space itself. According to NASA, the millions of pieces of hardware are flying at speeds around 18,000 miles per hour.
“We’re talking about weather satellites, we’re talking about other Earth observation science satellites that are in orbits where everybody wants to be, but they’ve been left stranded there,” Wilde said. “These things are as big as, definitely cars, but sometimes delivery vans or full-size trucks.”
At Florida Tech, researchers are trying to come up with methods to approach one of these fast-flying spacecraft, catch them and then safely remove or de-orbit the space junk without causing more space debris.
Wilde said the major challenge of collecting the trash humans leave in space is catching the spacecraft in a way that won’t create more debris.
“First of all, it’s hard to approach them because they are tumbling,” Wilde said.
In 2019, a UK aerospace company tested the idea of using a tiny harpoon to snag space debris and pull it back to a functioning spacecraft, and it was a success, according to the RemoveDebris project.
Wilde said putting these ideas into practice could happen within the next few years, if funding allows.
“We could probably fly one in two, three years. It’s just ... whether the funding is available and what the risk acceptance is,” he said.
There are also plans by NASA, DARPA and international companies to refuel satellites in space to allow the spacecraft to continue to operate for what they were designed.
Listen to the full episode of “Space Curious” below or wherever you listen to podcasts:
Space Curious is a podcast from WKMG and Graham Media that answers your intergalactic questions. Hosted by space reporter Emilee Speck, each episode is designed to inspire everyone, from the space curious to the space fanatics. Questions for the podcast can be submitted here.