Space is filling with junk and scientists have a fix

"As space activity accelerates, from mega-constellations of satellites to future lunar and Mars missions, we must make sure exploration doesn't repeat the mistakes made on Earth," says senior author and chemical engineer Jin Xuan of the University of Surrey. "A truly sustainable space future starts with technologies, materials and systems working together."

Growing debris and the problem of abandoned satellites

The environmental toll continues long after launch. Most spacecraft and satellites are never recycled, which means that large amounts of material are permanently lost when missions end. Many older satellites are shifted into "graveyard orbits," while others become drifting orbital debris that can disrupt the operation of active systems.

The authors argue that this approach cannot continue, especially with the increasing pace of private space missions. They highlight the need for a circular space economy, a model in which materials and equipment are created with reuse, repair, and recycling in mind. They also note that industries such as personal electronics and automotive manufacturing have already adopted similar ideas with considerable success.

"Our motivation was to bring the conversation about circularity into the space domain, where it's long overdue," says Xuan. "Circular economy thinking is transforming materials and manufacturing on Earth, but it's rarely applied to satellites, rockets, or space habitats."

Applying the 3 Rs to spacecraft, satellites, and space stations

According to the team, the foundation of a circular space economy lies in the 3 Rs: reduce, reuse, and recycle. Reducing waste would begin with building satellites and spacecraft that last longer and can be fixed more easily in space. They also suggest turning space stations into multifunctional centers where spacecraft can refuel, undergo repairs, or even have new components manufactured, which could cut down on the number of launches required.

The authors add that bringing spacecraft and space stations safely back to Earth for reuse would require better recovery systems, including technologies such as parachutes and airbags. They point out that equipment in space experiences significant wear because of extreme temperatures and radiation, so any part intended for reuse would need to pass strict safety checks.

Recovering orbital debris and using advanced technology for safer space operations

The researchers also recommend new efforts to gather orbital debris, such as using robotic arms or nets to collect fragments so the materials can be recycled. This would also help prevent collisions that create even more debris.

Data-driven tools will play an important role in this transition, the authors say. Information gathered from spacecraft could guide improvements in design and help limit waste, while simulation tools may reduce the need for expensive physical testing. They add that AI systems could help spacecraft and satellites avoid dangerous debris in real time.

Transforming the entire space system through innovation and global cooperation

The authors emphasize that a circular space economy represents a major shift in how the space sector works. Instead of focusing on single pieces of hardware, the entire system needs to be considered at once, from the materials used to how spacecraft are operated and retired.

"We need innovation at every level, from materials that can be reused or recycled in orbit and modular spacecraft that can be upgraded instead of discarded, to data systems that track how hardware ages in space," says Xuan.

"But just as importantly, we need international collaboration and policy frameworks to encourage reuse and recovery beyond Earth. The next phase is about connecting chemistry, design, and governance to turn sustainability into the default model for space."

This research received support from the UK Engineering and Physical Sciences Research Council, the Leverhulme Trust, and the Surrey-Adelaide Partnership Fund.