Electric Propulsion

Electric propulsion systems, characterized by their high specific impulse, are widely used in numerous space missions. These include orbit correction mechanisms for satellites in various altitudes and the provision of constant acceleration for deep space exploration spacecraft. However, due to its operational characteristics, the electric propulsion system emits plasma plumes that tend to expand at a wide angle. This phenomenon is problematic if such an expansion pollutes not only itself but also its parent spacecraft, decreasing the mission capability and shortening the expected lifespan of the spacecraft. 

Therefore, modeling the plasma plume expansion is of paramount importance in integrating electric propulsion into a spacecraft. A numerical simulation of the plasma plume can predict the plume's interaction with the spacecraft so that an appropriate countermeasure can be introduced to protect the spacecraft.

A new satellite orbit near Earth, namely very-low-earth-orbit (VLEO), can be a better alternative to other existing orbits with higher altitudes. Placing satellites in such orbit brings many benefits, such as reduced cost of launch and improved performance of satellite operation. However, one of the most fundamental problems of VLEO is the rarefied existence of atmospheric molecules that causes drag on the satellite. Without a method of drag compensation, this may result in premature orbital decay of the satellite. 

A game-changing technology that can circumvent this problem is Atmosphere-Breathing Electric Propulsion (ABEP). The system uses a thin atmosphere as the propellant rather than the traditional propellant of electric propulsion systems such as Xenon. Therefore, one of the challenges of ABEP is designing an efficient inlet for the collection and compression of rarefied atmosphere. As ABEP does not require Xenon during its operation, realizing this technology will significantly increase the spacecraft's lifespan and cargo capacity.

• Geonwoong Moon, Wonho Choe, and Eunji Jun. "Plasma plume simulation of an atomic oxygen-fed ion thruster in very-low-earth-orbit." Plasma Sources Science and Technology 32, no. 12 (2023): 125012 

• Youngil Ko, Sangwon Kim, Geonwoong Moon, Minwoo Yi, Kangmin Park, Younho Kim, and Eunji Jun. "Parametric study on the flight envelope of a radio-frequency ion thruster based atmosphere-breathing electric propulsion system." Acta Astronautica 212 (2023): 198-212. 

• Geonwoong Moon, Minwoo Yi, Kangmin Park, Younho Kim, Hyosang Yoon, and Eunji Jun. "Performance characterization and kinetic analysis of atmosphere-breathing electric propulsion intake device." Vacuum 212 (2023): 112066. 

• Geonwoong Moon, Eunji Jun, "Predictive Analysis of Atmosphere-Breathing Electric Propulsion using SPARTA Framework", In DSMC Workshop, 2023. (Sante Fe, NM, USA, Sep. 2023).

• Eunji Jun, Geonwoong Moon, Youngil Ko, Sangwon Kim, "Conceptual System Analysis of Very-Low-Earth-Orbit Satellites with Atmosphere-Breathing Electric Propulsion", In The 11th Asian Joint Conference on Propulsion and Power, 2023 (Kanazawa, Japan, Mar. 2023)

• Geonwoong Moon, Eunji Jun, "Characterization of Atmosphere-Breathing Electric Propulsion Intake Performance", In 13th Asian Computational Fluid Dynamics Conference, 2022. (Jeju, Republic of Korea, Oct. 2022).

• Geonwoong Moon, and Eunji Jun. "Plume simulation of atmosphere-breathing electric propulsion system." In AIP Conference Proceedings. vol. 2996. no. 1. AIP Publishing, 2024. 32nd International Symposium on Rarefied Gas Dynamics (Seoul, Republic of Korea, Jul. 2022).

• Geonwoong Moon, and Eunji Jun. "Performance study of intake device for atmosphere-breathing electric propulsion." In AIP Conference Proceedings. vol. 2996. no. 1. AIP Publishing, 2024. 32nd International Symposium on Rarefied Gas Dynamics (Seoul, Republic of Korea, Jul. 2022).