In the last years, INAF-Astronomical Observatory of Brera (INAF-OAB) has started to develop a glass slumping technology for the realization of thin and flexible mirror substrates for adaptive optical applications. In particular, the study was financed in the framework of OPTICON FP6 – E-ELT Design Study. With this approach we aim to reproduce with adequate accuracy the shape of an optically figured mould. At the end of the process we will have a thin, flexible and extremely lightweight glass mirror substrate. The shape of this glass shell will be of optical quality. In this paper we propose and discuss a technique for the manufacturing of stiff and lightweight mirror panels. Each panel shows a sandwich-like structure with two thin glass skins on both sides, the optical one being the substrate produced via glass slumping. This mechanical structure is ideal to limit the optics weight but keeping the quality of the substrate itself; key points for space-based applications. Moreover, the proposed phase of sandwich assembly is such that the glass shell does not lose its shape's quality. The approach here presented is derived from a previous development conducted by INAF-OAB for mirrors for Cherenkov Telescopes. We present the basic idea of the approach and some preliminary results obtained from tests realized.
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