296 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1961 



In the months that followed, numerous but not unexpected prob- 

 lems developed at Perkin-Elmer. Their responsibility certainly 

 transcended in difficulty almost any other that had been attempted 

 in the fabrication of aspheric optics. The outer plates of KzFS-2 

 had been designed to be thin in order to keep ultraviolet transmission 

 to a maximum, a fact that complicated the work because of the intri- 

 cate problem of supporting the thin plate. The task was all the more 

 difficult because the system involved four surfaces of very strong 

 individual powers on the same optical axis; as Dr. Baker later re- 

 marked, "It was a monumental accomplishment to make the four of 

 these work properly together." Finally, four of the six surfaces of 

 the corrector cell were strongly aspheric, presenting a real challenge 

 to the manufacturer. Perkin-Elmer felt originally that they could 

 generate the curves with a Meinel grinder. The surfaces were, how- 

 ever, too complex to be ground by machine, a fact that was to result 

 in some further delays. 



Meanwhile, the order for the mirror blanks had been placed with 

 Corning. In May 1957 Stefan Sydor, an expert in the manufacture 

 of optical materials, came to the Observatory. His first assignment 

 was to go directly to Corning and advise in the production of the 

 blanks. During the months that followed, he spent a good deal of his 

 time there supervising their fabrication. 



The Schott firm in Germany had received contracts for manufactur- 

 ing the glasses for the corrector cell and for the aspheric-surface 

 back-up plates against which the photographic film would be ten- 

 sioned to lie in the focal surface. They did a magnificent job on 

 both assignments. 



By June 1957 a sufficient number of the three types of glass blanks 

 had been received from Schott and from Corning to assure uninter- 

 mpted production during the remainder of the year. Military Air 

 Transport Service (MATS) had already flown 40 of the 48 large 

 glass disks for the corrector-plate assembly from Germany to Con- 

 necticut, and transported another 5 during the summer. This was one 

 of the many ways in which the Air Force cooperated with the Observa- 

 tory and facilitated the work of the program. 



Perkin-Elmer erected a new optical shop for fine grinding and 

 polishing of the optical parts of the camera, and by the sunmier of 

 1957 were grinding and polishing the test optics. Rough grinding 

 of the spheric surface of the corrector optics was done on a machine 

 especially built by Frank Cooke of North Brookfield, Mass. The 

 rough grinding of the primary mirrors was done at the main plant. 



During these months Sydor spent much of his time at the Perkin- 

 Elmer plant, working 10, 12, even 14 hours a day to complete, if pos- 

 sible, the first set of optics by late summer. 



