Fabrication of blanks, figuring, polishing, and testing of solid and segmented astronomical mirrors

JSC "LZOS" production facilities allow manufacturing optics from casting and annealing of blanks of Sitall CO-115M to final figuring and polishing. LZOS's Sitall capacities allow to produce over 100 tons a year. At the present time Sitall is widely used for manufacturing high-precision astronomical mirrors here at LZOS as well as at other companies. During 1997 - 2002 JSC "LZOS" has fabricated a number of astronomical mirrors including four primary mirrors with hyperbolic figure of 2050 mm (F/3) in diameter and two seconday mirrors of 645 mm (F/2.5) in diameter for Telescope Technologies Ltd, UK, primary mirror of 2280 mm (F/2.3) and secondary mirror of 753 mm (F/2) for the NOA telescope (Astronomical Institute -- National Observatory of Athens, Greece), primary mirror of 2650 mm (F/1.8) and secondary mirror of 938 mm (F/2.3) with an asphericity of 100 μm for the VST telescope (VLT Survey Telescope). We have also completed a number of astronomical mirrors with diameters up to 1300 mm for some European countries and the USA. The rms surface quality of all of the mirrors was in the range from 9 to 12 nm. We used comptuer controlled figuring, polishing and testing. Some mirrors were made of Sitall, producing by LZOS and some of Zerodur, Schott. Our largest current projects include 96 hexagonal segment blanks of 1019 mm x 55 mm for the SALT primary segmented mirror (Southern African Large Telescope), the M1 and M2 mirrors for the VISTA project (Visible and Infrared Survey Telescope for Astronomy) where primary mirror has 4 m diameter and secondary 1.2 m as well as 40 sub-mirrors of the LAMOST MB mirror of about 6.7 m x 6 m for Large Sky Area Multi-Object Spectroscopic Telescope (LAMOST).