Observational Arc-Length Effect on Orbit Determination for Korea Pathfinder Lunar Orbiter in the Earth-Moon Transfer Phase Using a Sequential Estimation

Abstract

In this study, the observational arc-length effect on orbit determination (OD) for the Korea Pathfinder Lunar Orbiter (KPLO) in the Earth-Moon Transfer phase was investigated. For the OD, we employed a sequential estimation using the extended Kalman filter and a fixed-point smoother. The mission periods, comprised between the perigee maneuvers (PM) and the lunar orbit insertion (LOI) maneuver in a 3.5 phasing loop of the KPLO, was the primary target. The total period was divided into three phases: launch–PM1, PM1–PM3, and PM3–LOI. The Doppler and range data obtained from three tracking stations [included in the deep space network (DSN) and Korea Deep Space Antenna (KDSA)] were utilized for the OD. Six arc-length cases (24 hrs, 48 hrs, 60 hrs, 3 days, 4 days, and 5 days) were considered for the arc-length effect investigation. In order to evaluate the OD accuracy, we analyzed the position uncertainties, the precision of orbit overlaps, and the position differences between true and estimated trajectories. The maximum performance of 3-day OD approach was observed in the case of stable flight dynamics operations and robust navigation capability. This study provides a guideline for the flight dynamics operations of the KPLO in the trans-lunar phase.

Practical Algorithms on Lunar Reference Frame Transformations for Korea Pathfinder Lunar Orbiter Flight Operation

“…In the left side of figure, the part where the color of the flight trajectory changes from red to blue is the point where the first deterministic delta-V is performed. The recent progress on various KPLO trajectory design and analysis can be found on Refs (Kim et al 2019a(Kim et al , 2019b(Kim et al , 2020a(Kim et al , 2020b(Kim et al , 2020c(Kim et al , 2021Bae et al 2020aBae et al , 2020cBae et al , 2021Hong et al 2020aHong et al , 2020bLee et al 2020aLee et al , 2020bLee et al , 2020cPark et al , 2020bSong et al 2020aSong et al , 2020b.…”

Development of Kinematic Ephemeris Generator for Korea Pathfinder Lunar Orbiter (KPLO)

“…Korea Pathfinder Lunar Orbiter (KPLO) is the first lunar spacecraft of Korea which will perform its missions over 100 km above the Moon's surface in 2022 year (Ju 2017;Lee et al 2017;Kim & Song 2019). The KPLO has several tasks, such as taking images of lunar surface, investigating lunar magnetic field distribution, radiation and surface compositions in polar orbits of the moon.…”