Material attributes that define performance and efficiency of spaceborne mirrors

Abstract

In addition to the classical parameters used for mirror substrate material selection, we discuss several other attributes critical to implementation of spaceborne mirrors for various environments. Often trades are either limited to the material and approach the designer has used in the past, whether or not it is optimum for the application, or are based on primary factors like specific stiffness and transient response. We look further at mission-critical attributes, including fracture mechanics, temporal drifts, deterministic implementation to design, inhomogeneity, anisotropy, polishability, compatibility with advanced coatings, and space heritage. We extend these considerations into discussion of increasing emphasis on designing to cost, available sizes and possible delivery timescales.