DeMi (Deformable Mirror Demonstration)

Characterize and calibrate the performance of a MEMS deformable mirror over a longduration on-orbit mission.

A recently deployed DARPA CubeSat seeks to demonstrate technology that could improve imaging of distant objects in space and allow powerful space telescopes to fit into small satellites. 

• Characterize and calibrate the performance of a MEMS deformable mirror over a longduration on-orbit mission.
• Measure mirror surface to <100 nm. Demonstrate the use of these mirrors as intended for high contrast imaging.
• Target stars: Vega, Arcturis, Sirius, Canopis, Alpha Centauri.

Deformable mirrors can adjust the shape of their reflective surfaces to correct for the effects of temperature and mechanical changes on a space telescope, improving image quality. The experiment will measure how well a MEMS deformable mirror performs in space, from the rocket launch through its time in orbit experiencing the thermal and radiation environment.

The primary mirror of the DeMi telescope is about an inch wide, and the deformable mirror surface is about the size of a dime. The DeMi payload can observe stars with the telescope and use an internal laser for calibration measurements of the deformable mirror. When the payload observes stars, the deformable mirror will keep the star centered on the imaging camera. The MEMS mirror has 140 actuators, tiny moving surfaces that control the mirror shape. Calibration measurements will track the performance using about 50 actuators over time in the space environment.

DeMi also aims to demonstrate wavefront correction, where the payload measures the wavefront, or shape of misalignments in the optical system. The deformable mirror corrects these errors by changing shape, acting like the opposite of a distorting funhouse mirror. After making observations, the DeMi spacecraft will downlink images from the wavefront sensors so operators can monitor the deformable mirror behavior from the ground.

• PLATFORM - Blue Canyon