Design and Development of 2U SPIRONE CubeSat for Verification of Navigation Signal Generator in LEO Environment and Marine Plastic Observation

This study aims to undertake the development of the SPIRONE Cube-satellite. The technical mission involves the development and validation of an S-band navigation signal generator for Low Earth Orbit (LEO), and the scientific mission is to observe marine plastics using Long-Wave Infrared (LWIR) and Short-Wave Infrared (SWIR) cameras. Traditional satellite navigation systems operate at medium Earth orbits around 20,000 km, where signals can weaken and become vulnerable to interference, impacting air navigation, shipping, and autonomous vehicles, potentially causing severe accidents. To address this, the project aims to explore LEO-based navigation by operating CubeSats in LEO to collect experimental data and conduct related research. Additionally, the CubeSat is equipped with LWIR and SWIR cameras to detect and help remove plastics in specific ocean areas. The SPIRONE CubeSat weighs approximately 2.48 kg [TBD] with a one-year mission duration, operating in a sun-synchronous orbit at 600km altitude. The onboard computer (OBC) uses FreeRTOS, and the satellite's hardware and subsystems are integrated for synchronized missions with the ground station. Simulation-based structural analysis, including random vibration and modal analysis, as well as shock tests, were conducted. In addition, simulation-based thermal analysis was conducted to assess the feasibility of mission execution in the target orbit. Power production was estimated considering the Noon-Midnight Orbit, ensuring sufficient margin. The ground station will be developed and utilized in-house, and there is also a plan to utilize the ground station of the Korea Aerospace Research Institute (KARI). Ham Radio Deluxe will be used for satellite control software, and in-house development is underway for satellite communication software. Additionally, through link budget analysis, it has been confirmed that there is sufficient margin. The SPIRONE CubeSat project conducted the Critical Design Review (CDR) in October 2023 and confirmed the design through the delta CDR in March 2024. Ultimately, it will be loaded onto the Nuri Rocket in 2025, and its mission execution and verification will be carried out in the LEO environment.