Korea’s LEO Satellite Explorations of the Earth’s Ionosphere and Thermosphere

KASI has been developing LEO satellite observation missions to study the Earth's ionosphere and upper atmosphere. These missions include SNIPE (Small scale magNetospheric and Ionospheric Plasma Experiment), SNIPE-2 (Small scale magNetospheric and Ionospheric Plasma Experiment-2), ROKITS (Republic Of Korea Imaging Test System), and ATHENA (Aurora THErmosphere ioNosphere for spAceweather). The successful launch of the SNIPE (Small scale magNetospheric and Ionospheric Plasma Experiment) mission in May 2023, featuring a formation flight of three nanosatellites, enables simultaneous observation of the spatio-temporal changes in plasma microstructures in the near-Earth space. It is still operational as of January 2025 and has provided high-quality observations of ionospheric plasma changes, particularly during the intense geomagnetic storms of May and October 2024. Based on this SNIPE, development of SNIPE-2, which will conduct stable near-Earth space exploration with six CubeSats, has also begun. Looking ahead, KASI’s upcoming mission, ROKITS (Republic Of Korea Imaging Test System), is scheduled for launch in 2025 to observe the Earth’s upper atmosphere with a wide-field aurora/airglow imager in visible wavelength (OI 557.7 nm and OI 630.0 nm). This imager will operate in a noon-midnight sun-synchronous orbit at an altitude of 600 km. The primary scientific goal of ROKITS is to define the boundary of the auroral oval and analyze various auroral shapes and the evolution of auroral features. Additionally, KASI is initiating an ambitious mission ATHENA (Aurora and Thermosphere: Energetics, Neutrals, and Atmosphere). ATHENA aims to advance our understanding of space weather forced from above and below using the observations by two threshold payloads: optical imagers operating in visual/infrared (KASI/ROKITS_IR) and far-ultraviolet (JHUAPL/GUVI+) wavelengths. ATHENA will fly these instruments in a near-polar, sun-synchronous orbit at about 640km. The key space weather parameters from the mission include auroral boundary and external energy input, atmospheric gravity waves, and vertical profiles of main atmospheric constituents. This presentation outlines the current and future LEO satellite exploration efforts of Korea’s Earth’s ionosphere and Thermosphere.