Challenges in Calculating the WCET of a Complex On-board Satellite Application

Calculating the WCET of mission-critical satellite applications is a challenging issue. The European Space Agency is currently undertaking the CryoSat mission, consisting of a radar altimetry satellite to be launched in 2005. This paper describes the challenges and the first experimental results of calculating the WCET of the Control and Data Management Unit (CDMU) subsystem of the satellite. This subsystem constitutes the central control unit of all the on-board data handling, as well as the attitude and orbit control system of the satellite, and must guarantee predictable behavior.