This paper addresses the problem of coordinating multiple spacecraft to fly in tightly controlled formations. The main contribution of the paper is to introduce a coordination architecture that subsumes leaderfollowing, behavioral, and virtual-structure approaches to the multi-vehicle coordination problem. The architecture is illustrated through an application of the ideas to the problem of synthesizing a multiple spacecraft interferometer in deep space. 1 Introduction The concept of multiple spacecraft flying in formation is emerging as an attractive alternative to traditional monolithic spacecraft, for both scientific and military applications. The multiple spacecraft approach has several advantages including, increased instrument resolution, reduced cost, reconfigurability, and overall system robustness. Some of the potential applications for formation flying include space-based interferometers and military surveillance instruments. Both NASA and the Air Force have identified space..