The Case for Aggressive Segmentation of the Primary Mirror of the Next Generation Space Telescope and Future ORIGINS Missions

Optical performance variations are considered from several factors including the gap between regular hexagonal mirror segments, the relative ability of segments of different size to be manufactured with low wavefront error, and expected mirror deformations. Additionally a weight variation function will be driven by recently postulated relationships which can be expressed so as to determine thickness of the mirror segment to satisfy: (1) polishing pressures (2) 1-g sage deflection, and (3) thermal induced stress as well as ancillary masses including actuators, wiring, and electronics. The result will be to survey the trade space of segment number and size for a range of apertures from 4 to 20 meters.