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At the University of California's Lick Observatory, we have implemented anon-sky testbed for next-generation adaptive optics (AO) technologies. TheVisible-Light Laser Guidestar Experiments instrument (ViLLaGEs) includesvisible-light AO, a micro-electro-mechanical-systems (MEMS) deformable mirror,and open-loop control of said MEMS on the 1-meter Nickel telescope at Mt.Hamilton. In this paper we evaluate the performance of ViLLaGEs in open- andclosed-loop control, finding that both control methods give equivalent Strehlratios of up to ~ 7% in I-band and similar rejection of temporal power.Therefore, we find that open-loop control of MEMS on-sky is as effective asclosed-loop control. Furthermore, after operating the system for three years,we find MEMS technology to function well in the observatory environment. Weconstruct an error budget for the system, accounting for 130 nm of wavefronterror out of 190 nm error in the science-camera PSFs. We find that the dominantknown term is internal static error, and that the known contributions to theerror budget from open-loop control (MEMS model, position repeatability,hysteresis, and WFS linearity) are negligible.

Performance of MEMS-based visible-light adaptive optics at Lick Observatory: Closed- and open-loop control