SATELLITE-TRACKING PROGRAM — ^HAYES 299 



various components had to be mounted in such a manner that they 

 would maintain the proper position relative to each other and relative 

 to the rest of the camera. At a number of conferences, Mr. Nunn, 

 representatives of Perkin-Elmer, and the Observatory staff developed 

 the details of the design of a series of holding rings for the corrector- 

 cell optics and the method for mounting the mirror. 



Early in 1957 a scale model of the camera was built and painted 

 in the brilliant colors that Nunn and Stinnett had decided upon. It 

 was a beautiful piece of equipment; Whipple and Hynek showed it 

 proudly to groups they addressed, and certainly it did much to 

 dramatize to the public the U.S. satellite-tracking program. 



The manufacture of the camera was one of the finest achievements 

 of American industry. Of entirely new design and of complex 

 structure, 12 of them had to be built without the construction of a 

 prototype, and without the testing of the individual components of 

 the system. The cameras were built almost concurrently, and the 

 first one completed had to work. And once the large components were 

 put into production, there was no opportunity to change any of the 

 details. 



By June of 1957 Boiler & Chivens were devoting more than 50 

 percent of their manufacturing facilities to the production of the 

 camera parts. Subcontractors in the Los Angeles area were simul- 

 taneously fabricating the frame and tube sections and machining 

 the castings for the corrector cells. Meanwhile, contracts had been 

 placed for the manufacture of the necessary electronic equipment 

 for the operation of the camera and the Norrman clock, including 

 the frequency control unit for the camera drive and the automatic 

 transfer switches for emergency power. 



The Observatory had by then also determined the type of film 

 that was needed for the camera. After a series of experiments 

 at the Agassiz Station of Harvard Observatory, the staff chose 

 the famous ID-2 emulsion, which is still used today for about half 

 of the satellite-tracking work. It provided the spectral distribution 

 that the Observatory needed, that is, reflected sunlight, and was a 

 faster film than any of the other emulsions then available. Some 

 40,000 feet of this film was ordered from Eastman-Kodak and put 

 in storage for tests of the camera in South Pasadena and at the New 

 Mexico field station in the fall. 



THE NORRMAN CLOCK 



By the summer of 1956 the details of the clock to time the photo- 

 graphs taken by the Baker-Nunn camera had been fairly well defined. 

 To replace the mechanical presentation of time in the Norrman clock 

 model 110, Robert Davis had developed an electronic sweep, in 



