324 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1964 



pounds; together they formed an object approximately 80 inches in 

 length and 6 inches in diameter. Its rapidly changing orbit required 

 that predictions of its passages be good; its poor visibility required 

 that a camera of exceptional capabilities be used in photogi-aphing it. 

 The predictions from Cambridge during the initial days of the satel- 

 lite's orbiting were not of high quality. In addition, the observers 

 had considerable difficulty in finding the satellite image on the plates ; 

 in part, this was due to inexperience and, in part, it was a consequence 

 of the satellite image on the film being quite small. 



As predictions were improved and as field procedures were refined, 

 more and more successful photographs were taken of this satellite and 

 of those launched subsequently. 



The first Baker-Nunn camera station was established in Las Cruces, 

 N. Mex., and the first photographic observation of Satellite 1957 al 

 made there November 26, 1957. There also the first observers were 

 trained to use the camera and related equipment and prepared to man 

 the other stations as soon as possible. 



From February through May, those other stations were established, 

 the 2d camera being shipped from California to South Africa on 

 Febmary 3, and the 12th to Hawaii on May 28. The last station 

 to begin photographing satellites was that in India, on August 29, 

 1958 ; although the camera had been shipped there on March 30, films 

 could not be taken earlier because of the monsoon season. 



As soon as all cameras were in the field, the observers carried out 

 tests, including the making of focus plates to be sent to Cambridge 

 for analysis. The results showed that all cameras, except that in 

 India for which no test films were yet available, yielded image diam- 

 eters in the center of the field of 60 microns or less, with an average 

 diameter on the order of 35 microns. Differences in focus between the 

 center and the edge of the field of the film indicated the need for 

 further adjustments and possibly for a refiguring of the backup plates 

 in several cameras. However, the image quality of the cameras was 

 good, demonstrating that each of them was capable of photographing 

 the faint United States satellites 1958 Alpha and 1958 Epsilson. 



While these tests proved that the cameras were more than adequate 

 to the task for which they had been designed, limited steps were taken 

 during the remainder of the IGY to improve their performance, in- 

 cluding visits by Mr. Sydor, the optical specialist of the Observatory, 

 to a number of stations to adjust the optical systems. 



One nagging fear had been that the KzFS-2 glass used in the outer 

 elements of the corrector cell of the camera would prove unduly 

 fragile as that glass was sensitive to acid staining and was "soluble" 

 in distilled water. Obviously, it was necessary to protect the glass 



