From recycling old satellites in space to turning rocket parts into fuel and sending debris back to Earth, researchers are finding new ways to tackle the growing problem of space junk.
For decades, we’ve littered space with parts of retired satellites and rockets to orbit the Earth. Today, this space debris poses an increasing threat to the satellites and spacecraft on which we depend. But researchers believe some of this debris could be turned into a valuable resource. According to the European Space Agency, there are currently more than 2,700 dead satellites orbiting Earth, as well as about 54,000 objects larger than a golf ball and an estimated 140 million objects larger than a speck of paint.
Over the years, many solutions have been proposed, ranging from new regulations to limit debris to techniques to remove it. But two EU-funded research initiatives, part of the European Innovation Council (EIC) to tackle space debris, are taking different approaches.
Through support for high-risk research, the EIC is helping scientists test radically new ways to deal with space debris, such as dismantling and recycling old satellites in space and “beaming” tiny pieces back into Earth’s atmosphere, where they burn up and disintegrate.
debris recovery
A team of companies and universities from the UK, Spain, Estonia and Sweden is exploring whether old satellites can be disassembled and reused directly in space. Their research, known as DEXTER, will launch in 2025 and is led by Leonard Felicetti, an associate professor of space engineering at Cranfield University in the UK.
“We’re cluttering the space with new objects,” Felicetti says. “What we want to do is reuse materials that we already have.”
Satellites are made from precious materials such as aluminum. Some eventually fall to Earth and burn up, while others remain in orbit for decades or even centuries. The idea is to recover those materials before they pose a long-term danger.
How to safely decompose space junk
The DEXTER team is tackling two important challenges: how to safely dismantle satellites in orbit and how to reuse their materials in meaningful ways.
One option is to reuse metal to build new structures in space, such as rigid frameworks that can support or extend satellites. Another, more ambitious idea is to turn the material into fuel.
To get there, the old satellites must first be captured and disassembled. Researchers are developing tools to make this possible, including robotic arms that can grab debris and lasers that can cut metal in space-like conditions. Initial tests are already underway in the lab.
Converting scrap metal into fuel is even more complex. One idea that British project partner Magdrive is exploring is whether aluminum could be converted into plasma and used in ion thrusters, a type of engine that uses charged particles to propel spacecraft.
“This is not a classic chemical fuel,” Felicetti said. “But it could provide a new way to power satellites using materials already in orbit.”
How to store or share such fuel is still an open question. One possibility is to create refueling stations in space where spacecraft can dock and receive fuel produced from recycled debris.
For now, we’re focused on proving the concept. The team hopes to demonstrate key technologies in orbit within the next few years.
beam the debris back down
Some researchers are looking into reusing debris, while others are focusing on completely removing debris, especially the small pieces that are the hardest to track and the most dangerous.
Some companies are already testing spacecraft that can attach to large debris and pull it back into the atmosphere. However, this approach does not work well for a much larger number of small pieces.
Led by French startup OSMOS X, researchers from France, Germany, Luxembourg and Spain are collaborating on an EU-funded initiative called ALBATOR. The researchers are testing whether they can use streams of charged particles to eject smaller pieces of debris out of orbit.
OSMOS X CEO Matthieu Cavellier calls this an “ion blower.” This is a device attached to a spacecraft that pushes debris back into Earth’s atmosphere, where it burns up.
The goal is to target debris down to millimeter size, such as debris left over from satellite collisions. Although small, they can cause big problems.
“Imagine two satellites colliding,” Cavellier said. “We need to act quickly to remove debris before it spreads.” Time is of the essence as each collision creates new debris that can cause further collisions. This is a cascade known as Kessler syndrome.
keep the space open
The ALBATOR team envisions a fleet of spacecraft that could deploy on demand, dive into debris clouds, and use short bursts of ion beams to clear them.
The technology is still being tested, with experiments planned in a vacuum chamber in Germany in 2027 ahead of a future space mission.
Space is becoming an increasingly busy and integral part of modern life, and the risks from debris are increasing. The most immediate benefit of both projects is to keep Earth’s orbit available and open for future generations.
For Felicetti, the goal is not just to remove hazards, but to rethink the way space is used as a whole.
“Space debris is a problem because it can collide with other satellites,” he says. “Our intention is to turn this responsibility into an opportunity.”
This article was originally published in Horizon, EU Research and Innovation Magazine.
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