EM characterization of a contactless active mirror for space telescopes

Contactless DM systems are widely the state-of-the art for adaptive optics systems of large format ground telescopes, yet their application to space telescopes (for a large format, segmented primary mirror with active optics) remains largely unstudied. In this contribution present the calibration and laboratory characterization of a contactless deformable mirror prototype for a space telescope segment. The prototype is LATT, the optical surface a 1 mm thick Zerodur mirror with 19 non-contact actuators over its 40 cm diameter. The system is calibrated by adapting existing ground-based calibration techniques for the prototype. The main innovation is in the validation of these techniques in a novel environment: the system is placed in a vacuum chamber and operated in low pressure conditions, in full magnetic levitation, free of any mechanical constraints.