Monday, May 9, 2011

Primary Mirror Repairs

On Wednesday April 27th, we received our repaired lightweighted primary mirror blank from ITT Geospatial Systems who generously donated time and money to the repair of the part. We received the part in September with cracks around the outer part of the mirror as shown below:

ITT sandblasted out the cracks such that the mirror now looks as follows in the areas where the cracks existed:

With the cracks removed the mirror is now less susceptible to damage in the grinding and polishing process as well as to damage due to random loads in everyday use. With the repairs completed the mirror is now moving to Optimax who generously agreed to grind and polish both our primary and secondary mirrors to the best fit sphere (the primary and secondary mirror are both hyperbolas, so before directly polishing to the hyperbolic shape, we usually polish to the best fit sphere). After Optimax finishes the work on the part, it will then pass to QED who graciously agreed to aspherize (figure to the hyperbolic shape) both our primary and secondary mirrors. Finally, at the conclusion of that process, Accucoat has agreed to donate their services to put a reflective coating on our mirrors.