The European Space Agency (ESA) has built and fired an electric thruster that could fuel satellites to fly in very low orbits for years on end.
Rocket motors are normally fueled by a mixture of gases containing freon and nitrogen, while the new electric thruster can ingest scarce air molecules from the top of the atmosphere for propellant.
A complete thruster had been developed to test the concept. The experiment was performed in Italy in a vacuum chamber, simulating the environment at 200 km altitude.
"This project began with a novel design to scoop up air molecules as propellant from the top of Earth's atmosphere at around 200 km altitude with a typical speed of 7.8 km per second," said Louis Walpot, an ESA engineer with this program.
The air-breathing electric thrusters could also be used at the outer fringes of atmospheres of other planets. It could draw on the carbon dioxide of, for instance Mars, when the thruster calls it by, the ESA said.