Requirements-driven satellite system design

The Skynet 5 system will provide military satellite communications to all three UK armed services, and is to be procured as a 'private finance initiative' (PFI). Though there are many PFI projects, this is the first time that such an approach has been taken for providing military satellite communications. The Defence Evaluation and Research Agency, Space Dept (now QinetiQ) has developed a simulation-based method for analysing payload designs based on requirements for communication services, as expressed by users. This method is implemented in a computer model called the Satellite Communication System Analysis Package (SCSAP), which has helped to size the 'public sector comparator' for Skynet 5. The paper presents SCSAP and its use in the context of a significant satellite system development. The simulator capitalised on the information exchange requirements (IER) capture process in Skynet 5 and helped MOD to size the public sector comparator for that procurement. The satellite communication system model (SCSM) was developed using a collaborative, prototyping approach, with the able and active support of its project sponsors - it has, as a result, enjoyed an unusually long life for an engineering simulator.