from what I read about the history and development of the Baker-Nunn satellite cameras, the big problem and one of the main reasons why the cameras were so good is the use of a fluorite corrector element that was highly water soluble. when a lens was found to be pitted beyond a reasonable point, a new one was shipped to the site and the damaged unit was shipped to be polished and then sent to another Baker-Nunn site needing a fresh corrector. the 2 Baker-Nunn cameras need to be 'refurbished' and I'm sure this will be a real rescue mission. Film was placed in a holder that is curved to match the focal plane please read FILM. On another note anyone have a couple used Losmandy clutch plates?? I need them for eyepiece sunshields on solar scopes. aloha Rob if anyone would like historic photos of the Haleakala Baker-Nunn site, let me know and I'll send them on