The base of the M1 mirror

For the optimal performance of the ELT the many components that attach the 39-metre segmented M1 mirror to the base structure of the ELT must be rigorously adjusted and tested by the engineering teams at ESO. The cell structures must carry the weight of every individual M1 mirror segment, some 1.4-metre across, and hold their positions in tandem with the other 797 for the ELT to work efficiently.