Abstract:Based on the characteristics of reentry satellite, there are two kind of time synchronization mode across the flight time. First, the combination of reentry capsule and apparatus capsule time mode. Second, apparatus capsule time mode. As a result, the key point is how to design the time system of the reentry satellite, and how to meet all the goals of the two time mode. The time system of reentry satellite includes time generation, time calibration, time broadcasting and time transmission. The design of time system aims at meeting the demand of time synchronization for the time users. This paper mainly discusses time synchronization demand, time-management model, time system architecture, the design of time system and the test verification of time system for the satellite.