Korea Acquires Core Technology for Nuclear-Powered Spacecraft

Nuclear Research Institute Achieves Success in Developing 10kW High-Power Electric Propulsion System

South Korea has secured core technology capable of developing nuclear electric propulsion spacecraft and satellites.

The Korea Atomic Energy Research Institute announced on the 15th that Dr. Chae Gil-byeong's research team from the Nuclear Physics Application Research Department successfully developed a 10kW-class high-power electric thruster, which can be used for nuclear electric propulsion, large satellites, and deep space exploration, after more than four years of research, and verified its key performance.

High-power electric thruster developed by the Korea Atomic Energy Research Institute. Photo by Korea Atomic Energy Research Institute

An electric thruster is a device that uses electrical energy to heat and accelerate fuel, then ejects it through a nozzle to generate thrust. Compared to conventional chemical thrusters, electric thrusters have lower thrust but significantly higher fuel efficiency, allowing for reduced fuel weight and increased payload weight. The high-power electric thruster developed this time has more than four times the fuel efficiency of chemical thrusters, and is expected to be utilized in future manned and unmanned spacecraft, large geostationary satellites, and more.

The research team constructed the high-power electric thruster with an anode, cathode, and an insulator separating the anode and cathode inside a permanent magnet. The electric current flowing from the anode to the cathode converts argon gas into plasma. The strong magnetic field generated by a 30 cm diameter cylindrical permanent magnet accelerates and heats the plasma argon gas, which is then ejected through a nozzle to produce thrust. At this time, the anode of the electric thruster must have heat resistance, and the cathode must be able to supply current stably. Furthermore, the material used for the insulator determines the stability of the plasma. Selecting an insulator material that can maximize and stabilize plasma performance has been a challenging issue in electric thruster development.

Vacuum chamber for performance verification of high-power electric thruster. Photo by Wonjaeryeokyeon 제공

The research team ensured heat resistance by manufacturing the anode, the component receiving the highest thermal load, from copper, and designed the cathode with thorium-tungsten material, successfully supplying current continuously for over two hours. The insulator was made of alumina (aluminum oxide) to improve plasma stability.

The thrust of 10 kW-class electric thrusters from advanced space technology countries is known to be between 300 and 600 mN (millinewtons; 1 mN is the force to lift 0.1 g). The research team built a performance evaluation system with a 2.6 m³ vacuum chamber simulating the cryogenic, vacuum conditions of space and confirmed a thrust of 200 mN. This is currently a stage where the key performance and characteristics of the technology have been demonstrated at the laboratory scale, and plans are in place to develop high-power electric thrusters over 10 kW and verify performance through a large vacuum chamber exceeding 60 m³.

High-power electric thruster argon plasma discharge image. Photo by Korea Atomic Energy Research Institute

Amid fierce international competition in space technology development, this research achievement is regarded as laying the foundation for technological independence in the field of high-power electric thrusters. Advanced space technology countries such as the United States, Europe, and Japan currently possess 10 to 100 kW high-power electric thruster technology, but it is controlled under the International Traffic in Arms Regulations (ITAR), making purchase or transfer impossible.

The Korea Atomic Energy Research Institute stated, "This research achievement is expected to contribute to the localization of related technologies through independent technology development," adding, "It is significant that we have acquired the capability to independently develop high-power electric thrusters."

This content was produced with the assistance of AI translation services.