Japan's new plasma engine could clean space junk contact-free

Researchers at Tohoku University in Japan have developed a novel plasma propulsion system designed to remove space debris without physical contact. The technology, called the "bidirectional plasma ejection type electrodeless plasma thruster," works by simultaneously ejecting two streams of plasma: one directed at space debris to slow and deorbit it, and another in the opposite direction to counteract the recoil force on the removal satellite. This balanced thrust allows the satellite to maintain stability and remain on target, addressing a key challenge faced by previous plasma-based debris removal concepts. The system also incorporates a special "cusp" magnetic field that contains and focuses the plasma, tripling the deceleration force compared to earlier experiments. Operating on argon gas, which is cheaper and more abundant than traditional propellants, the thruster offers an efficient and cost-effective solution for mitigating the growing problem of space junk. With around 14,000 pieces of debris in low Earth orbit posing collision risks to satellites and space stations, this technology