The definition of Concurrent Engineering that we have adopted for the Concurrent Design Facility is: 'Concurrent Engineering (CE) is a systematic approach to integrated product development that emphasises the response to customer expectations. It embodies team values of co-operation, trust and sharing in such a manner that decision making is by consensus, involving all perspectives in parallel, from the beginning of the product life-cycle.' Essentially, CE provides a collaborative, co-operative, collective and simultaneous engineering working environment. The concurrent engineering approach is based on five key elements: • a process • a multidisciplinary team • an integrated design model • a facility • a software infrastructure The spacecraft design is based on mathematical models, which make use of custom software and linked spreadsheets. By this means, a consistent set of design parameters can be defined and exchanged throughout the study, and any changes which may have an impact on other disciplines can immediately be identified and collectively assessed. In this way, a number of design iterations can be performed, and different design options can easily be analysed and compared.