English: Four segments of the giant primary mirror of the E-ELT undergoing testing together for the first time. The assembly, at ESO’s facility in Germany, provides a full-size mock-up of a small section of the E-ELT primary mirror and its support structures. During tests, the whole assembly can be tilted at an angle of up to 45 degrees. Standing some two metres above the floor, four test mirror segments have been placed on their supports to see how they behave together and when tilted.