The Korea Pathfinder Lunar Orbiter (KPLO), which is expected to launch in 2018 via international collaboration, will be the first Korean satellite to fly beyond Earth’s orbit. This work describes the preliminary design result of the lunar flight dynamics software for operational purpose (LUDOLP), the flight dynamics subsystem (FDS) of the KPLO mission. The system configuration of LUDOLP is discussed, including the details of each module’s functionalities, such as system management (SM), orbit determination (OD), orbit prediction (OP), event prediction (EP), maneuver planning and calibration (MPC), data simulation (DS) and fuel accounting (FA). The architecture of the ground segment (GS) for the KPLO mission is also briefly introduced. Building on the results of this study, the final version of LUDOLP will be developed in the near future to support the GS of the KPLO mission. The design of LUDOLP is expected to be directly applicable to Korea’s future deep space exploration missions to Mars and beyond.