Operations Update for the Deformable Mirror Demonstration Mission (DeMi) CubeSat

The Deformable Mirror Demonstration Mission (DeMi) CubeSat payload is a miniature space telescope designed to demonstrate Microelectromechanical Systems (MEMS) Deformable Mirror (DM) technology in space for the first time. MEMSDMscanprovidehigh-precisionwavefrontcontrolwithasmallformfactor,lowpowerdevicewiththe potential to be a key technology option for future space telescopes requiring adaptive optics. Applications of MEMS DMs in space include high-contrast imaging and optical communications. The DeMi payload contains a 140-actuator MEMS DM from Boston Micromachines Corporation whose performance can be measured with both an image plane wavefront sensor and a Shack Hartmann wavefront sensor (SHWFS). The key DeMi mission goals are to measure individual actuator wavefront displacement contributions to a precision of 12 nm and correct both static and dynamic wavefront errors in space to less than 100 nm RMS error. The DeMi mission has raised the Technology Readiness Level (TRL) of MEMS DM technology from a 5 to a 9. This paper summarizes payload data from the first year of in-space operations after briefly summarizing the DeMi optical payload design, calibration, integration and environmental testing results. Ground testing data shows that the DeMi SHWFS can measure individual actuator deflections on the MEMS DM to within 10 nm of interferometric calibration measurements and ground and space data can meet the 12 nm precision requirement for actuator deflec- tion voltages between 0-120 V [1]. Individual actuator measurements from space operations show the MEMS DM actuating in space with similar performance and measurement uncertainty to ground data. Differences between re- peated measurements of individual actuators have a standard deviation of 3-16 nm. Data from inital wavefront control experiments show the DeMi payload correcting wavefront errors in space to less than 150 nm RMS.