Defunct satellites, old rocket parts, and thousands of fragments from past missions are rapidly filling Earth’s orbit
These high-speed pieces of debris create a major threat to active satellites and spacecraft. With each new mission launched, the risk of collision increases, making space debris one of the biggest challenges for the future of space exploration and satellite communication.
Creating a solution
To address this escalating issue, a researcher at Tohoku University in Japan has developed a breakthrough in non-contact space debris removal. Usually, these methods involve grappling or physically capturing debris, and these approaches can be risky due to the high speed and unpredictable motion of orbiting junk. However, this new method takes a completely different approach.
Instead of grabbing the debris, the new system works by slowing it down. Once slowed, the debris begins to fall out of orbit and eventually burns up in Earth’s atmosphere. This process not only avoids direct contact but also reduces the complexity and risk associated with removal missions.
How it works
The central part of this new system is a specialised engine known as the bidirectional plasma ejection type electrodeless plasma thruster. This propulsion engine is designed to eject two powerful streams of plasma, one aimed at the target debris and the other in the opposite direction.
By shooting plasma at a piece of debris, the force gradually decelerates it. At the same time, the opposite stream counteracts the kickback force that would usually push the removal satellite away from the target. This balanced thrust keeps the satellite stable and ensures the plasma stream remains focused on the space debris.
Better efficiency
To further enhance the system’s effectiveness, a unique magnetic field structure known as a “cusp” was introduced. This configuration helps contain and direct the plasma, increasing the efficiency of the thrust. In laboratory tests simulating space conditions, this setup was shown to boost the deceleration force applied to debris significantly.
When the system was operated at high power under the cusp configuration, the deceleration force tripled compared to earlier models. This means space junk could fall out of orbit much faster, sometimes in just around 100 days, clearing paths for satellites and future missions far more efficiently than before.
Cost-effective and scalable
One of the most promising aspects of the new thruster is its use of argon as a propellant. Argon is cheaper and more abundant than many conventional fuels used in space propulsion, making this system not only practical but also cost-effective.
The ability to operate without direct contact, combined with better deceleration and affordable fuel, positions this system as a significant leap forward in tackling the global issue of space debris.
While the technology has so far been demonstrated in lab conditions, the results suggest that this approach could soon be deployed in real-world space missions. With increasing satellite traffic and the growing risk of orbital collisions, the need for reliable and safe debris removal systems is greater than ever.
![Figure 1 - The figure illustrates the diversity and multi-scale nature of the structures in the Galaxy. The first two lines are real astronomical images, which go from the galactic disk itself and down to the planet-forming disks. The last two lines are generated from numerical simulations and aim to understand and interpret the observations. [adapted from Facchini et al. 2025, Göller et al. 2025, Hennebelle et al. 2022, Lebreuilly et al. 2024, Molinari et al. 2016, 2025, Reissl et al. 2016]](https://www.openaccessgovernment.org/wp-content/uploads/2025/08/figure-100x70.png "Predictive modelling of galactic star and planet formation")
