COLUMBUS system integration and verification approach

This paper addresses the design and verification of the Columbus avionics architecture which has been successfully commissioned in-orbit after the docking of the Columbus module to the International Space Station on the 10 th of February 2008. The avionics of the Columbus module has been designed around a layered architecture and is based on state-of-the-art early 1990´s space technologies. The avionics provides the necessary controllability and observability of the vital and nominal functions of the module, including the interface with the space station. It also provides all the necessary resources for crew support and for the internal and external payloads utilisation. An important step towards the successful commissioning was the in verification approach followed during the assembly, Integration and Testing phase of the Project. The integration and validation philosophy used consists of an overall electrical test model (ETM), representing all the module functionalities, based on classic electrical model (EM) at box level mixed with simulators replacing the missing functionalities such as redundancies and environmental subsystems (thermal and environmental life control system). The ETM approach, based on EM box and simulators, had also the advantage to reduce the cost and to increase at the same time the verification flexibility. Moreover it allowed upgradeability without compromising verification quality. Special care had been given to the verification of the payloads racks through the ETM upgrade to support interface validation with the Columbus module even after it had been delivered to the ISS. Furthermore, all means for additional communication systems have been foreseen to increase the downlink and uplink capabilities of the Columbus Laboratory when external RF or optical terminals will be implemented. Finally, the Columbus avionics has been designed to allow future expansions such as the amateur radio for ISS (ARISS) project for which external antennas hav- - e been pre-installed.