Position actuators for the ELT primary mirror segments

On the ELT’s M1 mirror, each individual mirror segment will be installed on three position actuators, which  are built by the German company Physik Instrumente (PI). These actuators constantly adjust the position of the mirror segments through tiny, precise movements. A total of 2394 position actuators, three per mirror segment, will adjust the position of the mirror. This photo shows one of the position actuators, with a AAA battery shown for scale.