28 August 1998 Case for segmentation of the primary mirror of large-aperture space telescopes
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The hypothesis is tested: space telescopes with apertures larger than a few meters will have lower mass and cost and better optical performance if the primary mirror is aggressively segmented. Optical performance variations are considered from several factors including the gap between regular hexagonal mirror segments, the relative ability of different size to be manufactured with low wavefront error, and expected mirror deformations. A mass variation is derived to relate diameter and thickness of the mirror segments to satisfy mirror deflections and thermally induced stress. Mass estimation includes support structures, actuators, cabling, electronics, hinges, and latches. Cost is evaluated from several models previously proposed to address multiple mirror systems. The analyses conclude that there is a relatively-small optimum segment size that is independent of the dimensions of the overall array but which does depend upon the state of technology. It is further shown that a significant mass penalty will be incurred for segments that are either smaller or larger than the optimum size. Minimum mirror thickness is constrained, but engineering design principles for structural deflections and model frequencies otherwise dictate the design.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Edward E. Montgomery, Glenn W. Zeiders, "Case for segmentation of the primary mirror of large-aperture space telescopes", Proc. SPIE 3356, Space Telescopes and Instruments V, (28 August 1998); doi: 10.1117/12.324499; https://doi.org/10.1117/12.324499

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