The energy balance in a satellite needs to be designed properly for the satellite to safely operate and carry out successive missions on an orbit. In this study, an analysis program was developed using the MATLABⓇ graphic user interface (GUI) for nanosatellites. This program was used in a simulation to confirm the generated power, consumed power, and battery power in the satellites on the orbit, and its performance was verified with applying different satellite operational modes and units. For data transmission, STKⓇ-MATLABⓇ connectivity was used to send the generated power from STKⓇ to MATLABⓇ automatically. Moreover, this program is general-purpose; therefore, it can be applied to nanosatellites that have missions or shapes that are different from those of the satellites in this study. This power simulation tool could be used not only to calculate the suitable power budget when developing the power systems, but also to analyze the remaining energy balance in the satellites.

In this paper, a brief but essential development strategy for the lunar orbit determination system is discussed to prepare for the future Korea’s lunar missions. Prior to the discussion of this preliminary development strategy, technical models of foreign agencies for the lunar orbit determination system, tracking networks to measure the orbit, and collaborative efforts to verify system performance are reviewed in detail with a short summary of their lunar mission history. Covered foreign agencies are European Space Agency, Japan Aerospace Exploration Agency, Indian Space Research Organization and China National Space Administration. Based on the lessons from their experiences, the preliminary development strategy for Korea’s future lunar orbit determination system is discussed with regard to the core technical issues of dynamic modeling, numerical integration, measurement modeling, estimation method, measurement system as well as appropriate data formatting for the interoperability among foreign agencies. Although only the preliminary development strategy has been discussed through this work, the proposed strategy will aid the Korean astronautical society while on the development phase of the future Korea’s own lunar orbit determination system. Also, it is expected that further detailed system requirements or technical development strategies could be designed or established based on the current discussions.