The SpaceWire network standard is used in spacecraft communications and has been selected for future ESA satellites. In order to guarantee the safety and reliability of on-board systems, the designers have to make sure that all critical timing constraints are satisfied. The SpaceWire network is a wormhole based network which makes its timing analysis significantly complex. Some methods for computing upper-bounds of end-to-end delays of certain wormhole network models have been developed. However, those models require some explicit assumptions and dedicated real-time mechanisms which cannot be supported by the current SpaceWire networks. Moreover, some work has proposed analysis approaches for SpaceWire networks assuming the Round-Robin arbitration scheme only. In this paper, we focus on the priority based arbitration scheme instead and we propose a worst-case response time analysis to evaluate the end-to-end delays of traffic transmissions in SpaceWire networks. The corresponding proofs to our analysis are presented along with a case study. © 2012 ACM.