Recent planning for Constellation-X has driven the exploration of grazing incidence telescopes with focal lengths of 50 m or greater. Formation flying, wherein separate optic and detector spacecraft travel in formation, is one approach to implementing such long focal lengths. This approach eliminates the telescope tube that is an integral part of shielding against stray light. We consider the implications of formation flying with respect to stray light, and discuss design guidelines for baffling against stray light.