The mirror changes shape to correct for the effects of temperature and mechanical changes on a space telescope which improves image quality.
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.
SOURCES- DARPA Written By Brian Wang, Nextbigfuture.com
Brian Wang is a futurist, speaker, and successful blogger who covers a wide range of bleeding edge science and technology topics. His blog at Nextbigfuture.com receives 5+ million annual readers and is ranked as the #1 Science News Blog worldwide by Alexa, an Amazon company. Brian covers disruptive technology trends including Space, Robotics, Artificial Intelligence, Quantum Computing, Medicine, Anti-aging Biotechnology, and Nanotechnology. His work has been cited by futurist, Peter Diamandis and by marketing guru Seth Godin. Being a future enthusiast himself, he is currently a startup co-founder, Angel Investor, as well as advisor to several technology companies. Prior to blogging and lecturing on the future, Brian was a founder & CEO of a multi-million dollar technology consulting firm designing IT systems. He received a BS in Computer Science from University of Regina, and MBA from University of Calgary.
Disclosure: Brian has articles that give stock advice. He owns technology stocks and index funds.