TRAJECTORY DESIGN FOR THE KOREA PATHFINDER LUNAR ORBITER (KPLO)

The Korea Pathfinder Lunar Orbiter (KPLO) will be the first spacecraft for the Korean lunar exploration program. KPLO will fly in a low 100 km mean altitude lunar polar orbit. KPLO will utilize a 3.5 phasing loop transfer trajectory. This paper will describe several trade-off studies of critical parameters to minimize the Delta-V such as phasing loop option, trans-lunar inclination, 1st apogee altitude, SEM (Satellite-Earth-Moon) angle and periselene altitude for lunar orbit insertion. After lunar orbit insertion, KPLO will be placed into a mission orbit. These parameters were studied over a month-long launch period in December 2020 and the results are given. As a result, 3.5 loops with first apogee altitude of a 320,000 km provides minimum Delta-V. Low initial inclination, low SEM angle and low captured periselene altitude of LOI1 shows better performance.