Technologies for the fabrication of the E{ELT mirrors within the T{REX project

With its primary mirror with 39 m of diameter, the E–ELT will be the largest optical/near-infrared telescope in the world and will gather 13 times more light than the largest optical telescopes existing today. The different optical sub–systems of E–ELT, including the primary mirror based on hundreds of reflecting tiles assembled together, represent key components for the implementation of the telescopes. A huge amount of aspherical reflecting elements have to be produced with ”state of the art” figuring and polishing technologies and measured with proper metrological equipments. In the past couple of years, in the context of the T–REX project, a specific development program was carried out at the Brera Astronomical Observatory–INAF in order to address a numbers of technology aspects related to the fabrication of the E–ELT mirrors. In this paper we give a short overview of the activities that have been carried out. Other papers in this volume report on specific activities that have pursed within such a development program.