This paper presents a novel dynamic fault-tolerant scheduling model for real-time tasks on multiple observation satellites.In this model

the primary/backup policy is employed to tolerate one satellite's permanent failure at one time instant.On the basis of the fault-tolerant model

we propose a novel fault-tolerant satellite scheduling algorithm called FTSS.To improve the resource utilization

the overlapping technology is adopted.According to the satellite feature with time windows

we analyze the overlapping mechanism on satellites and combine them into FTSS.In addition

the FTSS employs the task merging strategies that are used to decrease the task count needed to execute and thus further enhance the schedulability.To demonstrate the superiority of our FTSS

we conduct simulation experiments to compare FTSS with three baseline algorithms.The experimental results indicate that FTSS efficiently improves the scheduling quality of others and is suitable for satellite fault-tolerant scheduling.