- In this paper, we present an integrated tool to support the high level design decisions concerning the assignment of instruments to satellites in an Earth Observation Program. This integrated tool features a rule-based expert system to model scientific synergies between measurements and engineering incompatibilities between instruments. We introduce two matrices: the science Design Structure Matrix (DSM) and the engineering DSM. Both matrices are calculated using the expert system, and provide insight into how to decompose the initial set of instruments into smaller tractable clusters. Then, each cluster of instruments is efficiently explored using metaheuristic algorithms (i.e. non-exact optimization algorithms that use heuristics to search the tradespace). We apply the methodology to the Earth Science Decadal Survey (DS) and identify a few architectures that are different from the baseline architecture and potentially better. 2011 IEEE.