Communiqué de presse

Turning of the M1 Cell at GIAT

25 juillet 1996

Each of the giant Zerodur mirrors for the four unit telescopes of the ESO Very Large Telescope (VLT) , with a diameter of 8.2-metres and a total area of more than 50 square metres, will be supported by a complex steel structure, referred to as the M1 Cell . This structure will also support the M3 Tower that protrudes from the central hole of the mirror and carries a flat mirror (M3) that serves to reflect the light towards the Nasmyth platforms on either side of the telescope. On these platforms are placed the heavy instruments that will record the light from celestial objects collected by the telescope.

The M1 Cells are now under construction by the consortium GIAT Industries, Branche GITECH and SFIM Industries (France). This company uses laser techniques for cutting and welding the single assemblies of the M1 Cell . This process is fully automatic and allows to generate very light and complex box-type structures starting from thin metal sheets. This ensures an excellent stability with a comparatively low weight and therefore ideal for the VLT M1 Cells . An M1 Cell structure weighs approximately 10 tons, and has a very high stiffness-to-mass ratio.

More information about the M1 Cell and related technical features is available on the VLT Web-page.

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