The European Extremely Large Telescope (ELT) construction1 is advancing and the M2, M3 and M5 cells are running the same path. The M22 and M3 mirrors are 4-meter class Zerodur® meniscus supported axially and laterally by mechanical whiffletrees. To allow low order corrections, axial support is provided with a warping harness system. Additionally, an electromechanical hexapod allows the movement in 5 degrees of freedom to optically align the telescope. The M2 Cell is ending the integration and test phase and approaching to the verification phase, where the highly demanding requirements will be checked. On the other hand, M3 cell is being assembled, taking advantage of the lessons learned during the M2 cell assembly. The M5 mirror is lightweighted silicon carbide elliptical flat mirror of 2.7 x 2.1 m², having the objective of folding the optical beams towards the Nasmyth platforms. Additionally, stabilizes the image movements induced by the telescope mechanisms and wind shaking vibrations. The M5 Cell is divided in two stages: the Tip-tilt and the Alignment Stage. The former allows to perform a fast-steering control while the latter provides active alignment capabilities to cope with the overall telescope structure misalignments The ELT M5 Cell is currently in the final design review, with qualification models for both stages successfully developed and tested. Preliminary results shown submicrometric resolutions for the Alignment Stage and around 5 nanometres for the Tip-Tilt Stage. This paper summarizes the design of the M2, M3 and M5 cells and presents its current development status.
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