The challenging development of lightweight glass mirrors for future X-ray telescopes

Due to requests from the scientific community, future X-ray telescopes need large effective areas (i.e. large mirror diameters) and good angular resolution (i.e. stiff structures to guarantee the correct mirror shape). Thereby also the mass limit of the launcher becomes an important factor to be considered. Previously used mirror technologies are not able to fulfill these challenging requirements. Consequently new technical approaches for an X-ray mirror production are under development. A promising technology is the hot slumping of thin glasses. The Max-Planck-Institute for extraterrestrial Physics (MPE) and the Aschaffenburg University of Applied Sciences started a cooperation to develop it at a suitable level for mass production of thin X-ray mirrors, addressing the challenging technical developments that the high precision mirror manufacturing requires. Design trades and first results are presented within this paper, including the thermal shaping process, the development of low stress iridium coatings and the mirror segments integration concept.