Improving X-Ray Resolution with XOSS
  Improving angular resolution is one of X-ray astronomy's big challenges. While X-ray interferometry should eventually vastly improve broad-band angular resolution, in the near-term, X-ray telescopes will sacrifice angular resolution for increased collecting area and energy resolution. Natural occultations have long been used to study sources on small angular scales, but are limited by short transit times and the rarity of transits. We describe here how one can make use of an X-ray Occulting Steerable Satellite (XOSS) to achieve very-high resolution of X-ray sources, conventional X-ray telescopes. Similar occulting satellites could also be deployed in conjunction with future space observatories in other wavebands. 
Craig J. Copi and Glenn D. Starkman