Evaluating design improvements for the ELT's primary mirror

In the large intergration hall at ESO's Headquarters in Garching, Germany, Paulo Ferreira is evaluating design improvements for ESO's Extremely Large Telescope (ELT) M1 mirror cable routing. Too large to be made from a single piece of glass, the 39-metre-diameter mirror will consist of 798 segments, each about 5 centimetres thick, measuring close to 1.5 metres across and weighing 250 kg, including its support. Since the segments have to work together as a single mirror, they require specific infrastructure and control schemes.