YEPUN is receiving its mirror

Another view of the fourth M2 Unit (delivered by Dornier in Germany) with the Dummy M2 mirror mounted for tests. The Dummy M2 mimicks the mass and inertia of the real mirror to allow tuning and adjustment of the advanced control system that makes it possible to "chop" the large mirror at high speed. (This digital photo was obtained on January 4, 2000).