Space Aerodynamics

Engineers are looking for ways to bring satellite orbits closer to Earth, namely in a very-low-earth-orbit (VLEO). Such orbit brings many benefits, such as reduced cost of launch and improved performance of satellite operation. However, the aerodynamic drag caused by the rarefied existence of atmospheric molecules must be compensated for the longer operation of VLEO satellites. 

As such, aerodynamics near Earth above 100 km in altitude should be analyzed accurately using particle-based simulations. Existing Computational Fluid Dynamics (CFD) will produce inaccurate drag calculations in this highly rarefied regime. Simulating flow conditions in this rarefied regime introduces unique complexities, particularly concerning surface properties influenced by gas-surface interactions (GSI). Therefore, achieving an accurate portrayal of GSI, encompassing factors such as scattering angle, energy accommodation, and potential reactions, becomes essential for precise surface property simulations.

Understanding the aerodynamics of VLEO satellites will allow aerospace engineers to predict the lifespan of satellites and the exact specifications requirements for propulsion methods necessary to compensate for the drag.

Planets other than the Earth in the solar system also have unique atmospheres with different compositions and degrees of rarefaction. In particular, the Martian atmosphere interests scientists the most for the host planet's resemblance and proximity to Earth. 

Traveling to Mars requires engineers to consider the aerothermodynamic effects on a rover entering the atmosphere for an Entry, Descent, and Landing (EDL) operation. Also, NASA's recent Ingenuity program (flying the first helicopter on a planet other than the Earth) epitomizes the importance of space aerodynamics. Because the Martian atmosphere composition is vastly different and rarefied from our own, an accurate computational analysis is necessary with the help of a particle-based simulation such as DSMC.

• 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).