Stray light shielding for formation flying x-ray telescopes

Recent studies and planning for a variety of x-ray astronomy missions (Constellation-X, XEUS, Generation-X) have driven astronomers to explore grazing incidence telescopes with focal lengths of 50 m or greater. One approach to implementing such long focal lengths is to employ formation flying: separate optic and detector spacecraft travel in formation. Formation flying removes the "telescope tube" which was an integral part of shielding the telescope from straylight. We consider the implications of formation flying with respect to straylight, and discuss some design guidelines for baffling the straylight. The Constellation-X mission is used as an example.