Air-breathing ion thruster. Credit: ESA / Sitael.

A team of scientists led by the European Space Agency (ESA) has successfully tested an electric thruster that is designed to ingest scarce air molecules from the top of the atmosphere for use as propellant.

The test has opened up new ways to power satellites flying in very low orbits for years.

In order to test the air-breathing electric propulsion concept, Italian company Sitael has developed a dual-stage thruster.

The test was conducted in a vacuum chamber at Sitael’s test facilities, simulating the environment at 200km altitude.

“This result means air-breathing electric propulsion is no longer simply a theory but a tangible, working concept, ready to be developed.”

A ‘particle flow generator’ has been used to collect the oncoming high-speed molecules by the air-breathing electric propulsion intake and thruster.

Polish company QuinteScience has designed the intake that collected the molecules, which were electrically charged accelerate and eject them to provide thrust.

No valves or complex parts were used to develop the intake and thrusters.

ESA representative Louis Walpot said: “At first we checked our thruster could be ignited repeatedly with xenon gathered from the particle beam generator.”

In the next step, scientists replaced portions of the xenon with a nitrogen-oxygen air mixture.

Walpot further added: “When the xenon-based blue colour of the engine plume changed to purple, we knew we’d succeeded.The system was finally ignited repeatedly solely with atmospheric propellant to prove the concept’s feasibility.

“This result means air-breathing electric propulsion is no longer simply a theory but a tangible, working concept, ready to be developed, to serve one day as the basis of a new class of missions.”

ESA’s Technology Research Programme and the Earth Observation Programme have supported the project.