On Sat, May 26, 2012 at 7:15 PM, Jed Rothwell <[email protected]> wrote:
> I did not know they had another one. That surely would have reduced the cost > of building a replacement, instead of repairing the one up there. Yes, built by two different contractors in the event one was destroyed in casting or grinding. Unfortunately, ground testing was insufficient to detect the aberrations. They considered launching the Kodak mirror or bring Hubble back; but, that was just a almost impossible task so, the made a corrective lens for the instruments which fitted between them and the prime mirror. The Grey Lady covered this well back in the early nineties if you want to research it. Oh, and, of course, Wikipedia: http://en.wikipedia.org/wiki/Hubble_Space_Telescope T
