Stephen L ODell, Ryan Allured, Andrew O Ames, Michael P Biskach, David M Broadway, Ricardo J Bruni, David Burrows, Jian Cao, Brandon D Chalifoux, Kai-wing Chan, Yip-Wah Chung, Vincenzo Cotroneo, Ronald F Elsner, Jessica A Gaskin, Mikhail V Gubarev, Ralf K Heilmann, Edward Hertz, Thomas N Jackson, Kiranmayee Kilaru, Jeffery J Kolodziejczak, Ryan S McClelland, Brian D Ramsey, Paul B Reid, Raul E Riveros, Jacqueline M Roche, Suzanne E Romaine, Timo T Saha, Mark L Schattenburg, Daniel A Schwartz, Eric D Schwartz, Peter M Solly, Susan E Trolier-McKinstry, Mellville P Ulmer, Alexey Vikhlilin, Margeaux L Wallace, and William W Zhang
In order to advance significantly scientific objectives, future x-ray astronomy missions will likely call for x-ray telescopes with large aperture areas (approx. = 3 sq m) and fine angular resolution (approx. = 1"). Achieving such performance is programmatically and technologically challenging due to the mass and envelope constraints of space-borne telescopes and to the need for densely nested grazing-incidence optics. Such an x-ray telescope will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 sq m) of lightweight (approx. = 2 kg/sq m areal density) high-quality mirrors, at an acceptable cost (approx. = 1 M$/sq m of mirror surface area). This paper reviews relevant programmatic and technological issues, as well as possible approaches for addressing these issues-including direct fabrication of monocrystalline silicon mirrors, active (in-space adjustable) figure correction of replicated mirrors, static post-fabrication correction using ion implantation, differential erosion or deposition, and coating-stress manipulation of thin substrates.