Comprehensive Flight Dynamics Activities and Enhancement for KOMPSAT-3 Mission Operations

Abstract

The KOMPSAT-3 is an earth observation satellite, developed and operated by Korea Aerospace Research Institute, which provides high resolution ground image of 70cm with 15km swath-width. It has been in normal operations without any anomalous events since the successful launch on May 18, 2012 by H-IIA. Flight dynamics activities play an important role in the safe and stable mission operations. And, precise orbit information is also required to satisfy the mission objectives. To ensure this, a lot of efforts were made during launch and early operations phase of KOMPSAT-3. The operational results and lessons learned throughout this early phase are fundamental basis for the normal mission operations. This paper describes the comprehensive flight dynamics activities and operational results for the launch and early operations phase of KOMPSAT-3, which include initial orbit determination, orbital maneuver, precise orbit determination and validation, and conjunction analysis. At the initial phase, operational orbit determination was carried out using ground tracking data and GPS navigation solution. And, both in-plane and out-of plane maneuvers were executed in order to change the orbit from the injection orbit to the mission orbit. In addition, the accuracy of precise orbit determination was evaluated by overlapping method using GPS raw data of KOMPSAT-3 and international GNSS service data from worldwide-distributed ground stations. Based on the reference orbit data from precise orbit determination, the functional requirements of the on-board GPS receiver were also evaluated using real flight data. Regarding space situational awareness, conjunction assessment system has been operational on a daily basis. Thanks to the international support of JSPOC, the upcoming close approach events are predicted and analyzed in more detail. After the commissioning phase, the automated system was adopted in order to reduce the operational workload and maximize the efficiency. The automatic process integrated the several routine processes which are necessary for daily flight dynamics activities, including precise orbit determination, orbit data generation, conjunction assessment, and orbit trending and evaluation. Automation is now fully operational for KOMPSAT-2 and KOMPSAT-3 mission support. Moreover, it is applicable to future LEO satellite mission with plug-and-play scheme. Lessons learned from the operational results of KOMPSAT-3 can be a good reference for the future mission preparations.