Adaptive Optics A membrane mirror assembly is described that has a membrane deflected by a region of electrostatic actuators consisting of conducting pads The procedure for fabrication of typical membranes is described and involves evaporation of the material onto a substrate in a vacuum chamber Parametric equations developed from basic vibration theory are given for establishing transient and steady state performance criteria Experimental data using both titanium and nickel test membranes shows that the performance satisfies the predicted requirements