System challenges in the development of low-cost planetary missions

It is generally acknowledged that new challenging scientific goals combined with the variety and complexity of newly proposed instruments are increasingly dictating the system and mission design of space missions in general, and of planetary exploration missions in particular. On the other hand, economical restrictions in public budgets, decreasing political support for scientific space research and technological hurdles are neutralizing and constraining the scientific momentum. New low-cost planetary missions, which despite the above mentioned constraints can guarantee an excellent scientific return, are requiring a new approach in system engineering and management, by applying innovative and creative spirit but keeping the cost awareness high during the complete development process. The present paper discusses a collection of the new challenges surfacing in the various fields of system design for future planetary missions.