Can We Solve the Satellite Air Pollution Problem? Here Are Four Promising Solutions

The rapid expansion of the space industry has brought an unforeseen issue: air pollution from burning satellites. Each time a satellite re-enters Earth's atmosphere and disintegrates, it releases materials that contribute to pollution, potentially damaging the ozone layer and affecting climate stability. With megaconstellations like SpaceX’s Starlink adding thousands of satellites into orbit each year, this problem could grow unless new solutions are explored and implemented. Here are four innovative approaches that scientists and engineers are exploring to mitigate satellite-induced air pollution.

Recoverable Satellites: A New Approach to Reuse

Space Forge, a U.K.-based startup, has proposed an intriguing alternative to the current method of discarding satellites by letting them burn up upon reentry. Instead, Space Forge is developing satellites with foldable heat shields designed to survive the intense heat of atmospheric reentry. These shields, crafted with resilient materials, are capable of protecting not only the satellite’s components but also the valuable in-orbit manufacturing materials that companies increasingly want to bring back to Earth. If implemented on a larger scale, recoverable satellites could substantially reduce the amount of harmful satellite ash produced in the atmosphere.

Andrew Bacon, Space Forge’s chief technology officer, believes that a future in which satellites are routinely recovered and reused could be transformative. As he explained, “Moving towards the strategy of returning satellites intact, refurbishing them, and relaunching them could be part of the solution.” However, the transition to recoverable satellites would require significant technological advancements, particularly in creating reliable reentry systems. Currently, only select spacecraft, such as crewed capsules and SpaceX’s Cargo Dragon, are built to return intact from space. This concept, however, could reshape the industry by reducing satellite waste and extending the life cycle of satellite materials.

In-Orbit Recycling: Transforming Space Junk into Fuel

While recovering satellites is one option, recycling them directly in orbit offers another solution. Neumann Space, an Australian startup, is pioneering an electric propulsion system that can use satellite debris as fuel. This system utilizes a technology called cathodic arc, commonly used in thin-film deposition, which works by evaporating material from a solid, conductive substance and ionizing it into a plasma. For in-orbit recycling, this means that metals, such as aluminum from old satellites, can be collected, melted, and repurposed as fuel to power other spacecraft.

This approach would require a fully operational orbiting foundry—an in-space manufacturing hub capable of processing metal debris and supplying it to satellites equipped with the new thruster system. This ambitious idea, currently funded by a NASA Small Business Innovation Research project, would need collaboration with other space players like Astroscale, a company focused on active debris removal. If successful, this technology could lead to the first demonstration mission, proving that in-orbit recycling is feasible and could address the growing threat of space junk in addition to reducing the number of satellites re-entering Earth’s atmosphere.

Engineered Reentries: Controlling the Way Satellites Burn

For a more immediate solution, some researchers are exploring ways to reduce the environmental impact of satellite reentry by controlling the reentry process. Satellites typically burn up at altitudes between 60 and 80 kilometers (37–50 miles), where chemical byproducts can linger for decades, slowly descending through the atmosphere and posing environmental risks. However, by adjusting the reentry altitude and angle, satellite operators could influence the breakdown of satellite materials, reducing the generation of harmful metallic oxides.

Minkwan Kim, an astronautics professor at the University of Southampton, has suggested that satellites disintegrate at lower altitudes—between 20 and 30 kilometers (10–20 miles). This would allow the particles to descend to the ground more quickly, minimizing the impact on atmospheric chemistry. Adjusting the angle of reentry could also reduce the temperature and allow more metal to break down into relatively harmless particles rather than oxides, which pose a higher environmental risk. Such engineered reentries represent a straightforward approach to reducing the chemical pollution associated with satellite reentry while still safely removing defunct satellites from orbit.

New, Environmentally Friendly Materials

Rethinking the materials used to build satellites may be one of the most sustainable long-term strategies. Aluminum alloys, currently standard in satellite and rocket construction, release metallic oxides when they burn, contributing to atmospheric pollution. Scientists are beginning to research alternative materials that could have a lower environmental impact. However, material substitution in satellite construction is complex; any new material must be light, strong, and durable enough to withstand the harsh conditions of space while meeting specific performance requirements.

One major challenge is predicting the environmental effects of any new material. For instance, while alternative metals or composites may reduce certain pollutants, they could introduce new types of pollution. Developing environmentally friendly materials for space applications requires rigorous testing and modeling to ensure they won’t create similar or unexpected environmental issues.

The Future of Cleaner Satellites

As we push forward in our pursuit of space exploration and satellite-based technology, these innovative solutions offer promising pathways to address satellite pollution. From recoverable satellites to in-orbit recycling, engineered reentries, and new materials, each approach could play a role in reshaping the future of space activities in a more sustainable way. While some of these solutions, such as in-orbit recycling, remain years from practical implementation, others, like engineered reentries, could be adopted sooner with relatively minimal adjustments to existing practices.

Addressing satellite-induced air pollution will require collaboration across the space industry and a commitment to environmental responsibility, but with the pace of technological advancements, there’s hope that we can continue exploring space without compromising the health of our planet.