SATELLITE-TRACKING PROGRAM — HAYES 325 



from rain. The lens cover, therefore, had to be kept on the corrector 

 cell at all times except during actual photography, and the air-drying 

 system for the camera kept in good working condition. Later, special 

 desiccators would be installed. At each station, however, some highly 

 individual methods were used to ensure that the outer lens was kept 

 dry ; at one, the observers found that a quick swipe of the lens with a 

 baby's diaper was highly effective. 



In any case, experience proved that although the outer lens was 

 inevitably pockmarked to some extent by moisture in the air, the loss 

 of transmission was very small — not more than 10 percent. Although 

 acceptable, this was not ideal, and later means would be found to pro- 

 tect the lens better. 



Another problem was that the camera was "blind" to the observer. 

 In other words, there were no means whereby the observer could see 

 what the camera was photographing. To remedy this situation, late 

 in 1958 the Observatory shipped 6-inch aperture telescopes to the 

 stations. One of these was attached to each camera so that the axes 

 of the two telescopes were parallel. The observer could then Avatch 

 what the Baker-Nunn camera was photographing and during a transit 

 make any necessary adjustments in the tracking mechanisms so that 

 the image of the satellite would remain roughly centered on the film. 

 This procedure proved to be extremely valuable in directing the 

 camera to photograph newly launched satellites for which predictions 

 might be somewhat inaccurate. 



A third difficulty involved the Norrman time standard. In part, 

 this was a consequence of the heavy strain that was placed on the 

 mechanism itself. For example, a transformer proved to be sub- 

 standard to the needs of the system and had to be replaced in all the 

 clocks. In part, also, it was the result of inadequate power supply to 

 some of the stations. Consequently, the amplifier to the clock had 

 to be modified, and other means found to ensure a constant and steady 

 power. 



The film chosen for the camera was the famous ID-2, which pro- 

 vided the spectral distribution needed and was extremely fast. Never- 

 theless during the remainder of the IGY consideration was given 

 to several other types of film. Early in 1958, Eastman Kodak pro- 

 posed the use of their S.0.1200 emulsion. Tests at the New Mexico 

 station proved that the film was about twice as fast the ID-2. How- 

 ever, the manufacturer encountered serious production difficulties that 

 prevented production of the film in sufficient quantities. Later that 

 year, one other film was tried : a Dupont emulsion coated on a "cronar" 

 base. It was unsuitable. In addition, tests were made to determine 

 the possibility of photographing very bright satellites during the day 

 by using an infrared-sensitive film together with an infrared filter 



