SATELLITE-TRACKING PROGRAM — HAYES 323 



graph the object. Thus another satellite was rediscovered by 

 Moonwatch. 



Wlien the third Eussian satellite (Satellite 1958 Delta) was launched 

 on May 15, 1958, a large number of Moonwatch observations made it 

 possible to determine that the satellite was accompanied by at least 

 three components. On November 21, all Moonwatch teams were 

 alerted to observe the last few revolutions of 1958 81. Many such 

 observations were received, including two made during what is be- 

 lieved to have been the next to last revolution of the satellite ; these 

 sightings were by teams in Wichita, Kans., and Albuquerque, N. Mex. 



In the late spring of 1958 only three observations were made of 

 Satellite 1958 Epsilon; these were not sufficient for the preparation 

 of predictions for the Baker-Nunn stations. Fifteen Moonwatch 

 teams were assigned to concentrate on this object and a number of ob- 

 servations were made shortly thereafter. The satellite, however, 

 proved to be so erratic that special observations of it were again re- 

 quested m December. This time, however, Moonwatch was unable 

 to find it. 



Within 2 days of the launching on February 17, 1959, of Satellite 

 1959 al (Vanguard II), Moonwatch teams were called upon to de- 

 termine whether the third stage component of the rocket, Satellite 

 1958 a2, was in fact in orbit. By the end of the month a number of 

 teams had made observations of the object and from these the Ob- 

 servatory was able to prepare preliminary ephemerides for the Baker- 

 Nunn stations. Subsequent photographs confirmed the existence of 

 the satellite. 



These are but a few of the noteworthy achievements of the Moon- 

 match network during the IG Y and the IGC. 



BAKER-NUNN CAMERA STATIONS 



Explorer I offered the first significant challenge to the capabilities 

 of the Baker-Nunn camera that could reasonably be expected to be 

 met. Satellite 1957 a2 (Sputnik I) had been a 22.8-inch sphere, 

 probably painted black, that during its brief lifetime of 92 days could 

 not be successfully photographed by the only Baker-Nunn camera 

 then in operation, first at South Pasadena, Calif., and then at the Las 

 Cruces station in New Mexico. The rocket case (Satellite 1957 al) 

 had been a large object visible to the naked eye and easily photo- 

 graphed by the camera. Satellite 1957 Beta consisted of the payload 

 of Sputnik II and the rocket case, which never separated; together 

 they were probably 85 feet long and weighed as much as 4 tons. 

 Again, the satellite was visible to the naked eye and easily photo- 

 graphed. 



Satellite 1958 Alpha consisted of a payload 22 inches in diameter 

 and about 10.5 pounds in weight, and a cylinder of approximately 30 



