Abstract: Abstract： Configuration based on internal 1553B bus is widely usede in attitude and orbit control system of international spacecraft. Aiming at the problems of poor integration,poor extensibility and poor generality caused by the nonuniform bus data protocol of attitude and orbit control system for Chinese spacecraft,internal 1553B Bus data protocol based on ECSS is designed.A fourlayer data protocol architecture is proposed based on the analysis of the data sevice requirments of the internal bus of attitude and orbit control system.The design of the bus protocol based on ECSS in application support layer and link sevice layeris is mainly introduced and the application of the protocol is explained.The application of this international standard protocol is helpful to standardize the 1553B data protocol in attitude and orbit control system for Chinese spacecraft.The integration and extensibility of the attitude and orbit control system and the generalization of onboard equipment(including software) are improved.

Key words: Keywords： attitude and orbit control system, 1553B bus protocol, ECSS, architecture