Cost scaling of finely segmented filled aperture large telescope observatories: a TMT study

Abstract

Previous studies of the scaling of the costs of ground based optical observatories suggest that total costs scale as the primary mirror diameter to a power between 1.7 and 3.0. It has been suggested that observatory costs may scale as primary mirror diameter squared reflecting the dependence on thinner mirrors in the current generation of observatory design. Upon completing the detailed cost estimate in support of the Preliminary Design for the Thirty Meter Telescope, an in depth study was undertaken to understand the sensitivity of the estimate to mirror diameter and thickness in addition to other leading parameters of TMT such as segmentation, primary focal ratio, and enclosure diameter. Based upon this analysis, and expressing the costs scaled solely to the mirror diameter, our analysis suggests that the TMT design scales effectively as the diameter to the power 1.2. We will describe the assumptions used to guide this study, the methods used to build the cost model, and the general results of the model.

Managing a big ground-based astronomy project: the Thirty Meter Telescope (TMT) project

“…Simple scaling by the primary mirror area from the Keck costs, a common rule-of-thumb procedure, suggested unacceptable costs. This subject is discussed elsewhere in these proceedings [11,12] . TMT carried out the development of technical requirements and the Conceptual Design in 2005, leading to a successful Conceptual Design Review in May 2006.…”