New Satellite Engine Could Use Earth's Atmosphere to Stay in Orbit Indefinitely

Francesco Romano, a PhD researcher at the University of Stuttgart, described a radio frequency helicon plasma thruster designed for very low Earth orbit. The concept uses atmospheric oxygen and other gases as propellant instead of carrying xenon fuel. This approach is part of a class known as atmosphere-breathing electric propulsion, which converts thin air into plasma to generate thrust. The design aims to allow satellites to remain in orbit indefinitely without a conventional onboard supply of fuel. Romano tested three intake designs in wind tunnel simulations to determine which best collected particles. The specular intake performed best, gathering roughly ninety-four point three percent of air particles and maintaining efficiency after a fifteen degree tilt. Laboratory work in a vacuum chamber simulated specific atmospheric concentrations found at high altitudes. The engine produced steady plasma streams using only fifty to sixty watts of radio frequency power. A birdcage antenna structure ensured that ninety-nine percent of delivered electrical power entered the thruster without needing a standard neutralizer component. Laboratory success does not guarantee that the system will function reliably during an actual mission. The upper atmosphere varies due to day-night cycles, latitude, and solar activity, creating conditions that remain difficult for engines to handle. Atmospheric oxygen is highly oxidative and can corrode standard engine components like electrodes and grids. Although models suggest indefinite operation between one hundred ninety and two hundred fifty kilometers, the technology has not yet been proven in space. It remains a research concept rather than a deployed solution for keeping satellites aloft.