PACT: the actuator to support the primary mirror of the ELT

Abstract

The European Southern Observatory (ESO) has started technology development for their next generation optical telescope. Due to its ultra large collecting area, The European Extremely Large Telescope (E-ELT) will require a paradigm shift in telescope design to keep the overall program cost at an acceptable level. The E-ELT will feature a 42 meter segmented primary mirror and will make extensive use of active and adaptive optics. Each primary mirror segment will be supported by three actuators that control piston and tilt. TNO has developed a low cost nanopositioning actuator (PACT) for the primary mirror segments. The actuators will be tested by IAC and ESO, with support from TNO, under operational conditions in a Wind Evaluation Breadboard (WEB) at the Roque de Los Muchachos observatory in La Palma.