The concept of an "electric jet engine" that generates thrust using only electricity without burning fuel has moved a step closer to reality. It propels forward by expelling intensely heated air to the rear and is drawing attention because, unlike conventional aircraft engines, it can produce thrust without carbon emissions.
Professor Lee Anna of the Pohang University of Science and Technology POSTECH department of mechanical engineering and Senior Researcher Kang Hong-jae of the Korea Institute of Machinery & Materials (KIMM) said on the 11th that their team had realized, for the first time in the world, an air-breathing electric propulsion technology operating at atmospheric pressure. The results were published in January in the international aerospace journal "Advances in Space Research."
The aviation industry is considered a major source of carbon emissions. Current aircraft engines draw in outside air, burn fuel to create high-temperature, high-pressure gas, and expel it to the rear to gain thrust. This process produces various emissions, including carbon dioxide. As carbon neutrality has emerged as a global task, interest has grown in new propulsion technologies that can move aircraft without burning fuel.
One of these is plasma electric propulsion. Plasma is a state in which gas is ionized by electricity and is often called the "fourth state of matter." If this plasma is accelerated and pushed backward, thrust can be obtained. Because it does not burn fuel, it has the advantage of producing no exhaust gases, but research so far has mostly been conducted in outer space or very low Earth orbit, where air is scarce. That is because it has been difficult to maintain stable discharge in atmospheric-pressure environments where air is plentiful.
The research team overcame this limitation with a rotating gliding arc (RGA) structure. They formed a rotating plasma flame to enable stable discharge even at atmospheric pressure. In the newly developed thruster, outside air flows in and creates a strong swirling flow, during which rotating plasma is generated. The plasma then rapidly heats the air and pushes it backward, producing thrust.
The team confirmed that plasma discharge remained stable under atmospheric conditions and successfully achieved continuous operation even when the internal pressure of the thruster rose to about 5.7 atmospheres. The maximum thrust measured at that time was 2.5 N (newtons). The thrust-to-power ratio was 708 mN/kW (millinewtons per kilowatt), about 10 times higher than existing plasma thrusters.
This achievement is meaningful as the first case showing that plasma electric propulsion is not confined to outer space but could be practically used within Earth's atmosphere. If the technology advances further, it is expected to be applied to electric aircraft, long-endurance unmanned aerial vehicles, and next-generation eco-friendly air mobility. In particular, it could become a new alternative for zero-carbon, fuel-free propulsion in the aviation sector, where carbon reduction is urgent.
Professor Lee Anna said, "It is highly meaningful that we implemented the concept of an electric jet engine that generates thrust using only electricity without burning fuel as a system that can actually operate." Senior Researcher Kang Hong-jae also noted, "There is great potential for expansion not only to long-endurance unmanned aircraft and next-generation air mobility but also to thrusters that use air in very low Earth orbit."
References
Advances in Space Research (2026), DOI: https://doi.org/10.1016/j.asr.2026.01.005