The earth observation satellite has been designed to have powerful ability, which produce huge amount of data. The traditional ground station data receiving system can hardly fulfill the demand of all kinds of terminal users, and the data relay system based on geostationary satellite gradually becomes a considerable solution. This paper proposes a greedy strategy based on-line scheduling algorithm for geostationary data relay system to schedule earth observation data download, which considers a trade-off among throughput, fairness, and the quality of service.

An on-board autonomous task planning system is designed and implemented in this article, aiming at the problem that the current remote sensing satellite needs complex instruction support to perform tasks and depends on the ground system too much. The complex earth observation task description and injection decomposition modules are designed in the system. No more than 128 ordered points describe the curve area task or irregular polygon area task, and the complex task is decomposed into several strips according to the satellite imaging width. Then, the task’s orbit, attitude, mobility, energy, and time constraints are calculated through the modules of on-board orbit prediction, agile attitude calculation, track planning, energy prediction, and visible arc calculation. Finally, the on-board autonomous task planning and execution are completed through task solution space search and metatask command generation modules. The on-orbit flight verification is carried out on the high-resolution multimode (GFDM) satellite. The results show that this paper’s on-board autonomous task planning system can complete complex task injection and autonomous planning and finally execute.

A satellite mission instruction generation algorithm based on a flexible weighted directed graph has been proposed. This algorithm can sort the instruction into sequence according to the instruction execution relationship with constraints, which can promote satellite operation performance of the ground station. Concepts like flexible edge, flexible zone, and implement zone were introduced, and the flexible weighted directed graph (FWDG) model was proposed. Based on this model, the satellite instruction sequence generation algorithm was designed. After practice and research, the result showed that according to the new algorithm, the instruction sequence can be consistent with all implement zones, consequently guaranteeing the correctness of the sequence.