Secondary mirror
M2 segments: cut to match modules of 7 or 19 M1 segments
- reduce field effects of combined M1 and M2 segmentation
- 108 to 294 segments
same figuring processes as for M1 segments, production rate relaxed by factor 7 or 19
Material: glass-ceramics; SiC 30-40 mm plates or simple lightweight structure to be investigated.