SATELLITE-TRACKING PROGRAM — HAYES 291 



servations a mathematical description of the orbit of the satellite so 

 that predictions of its future passages over specified places could be 

 made. Communications would send the predictions to the Moon- 

 watch teams and the Baker-Nunn camera stations and receive from 

 them their observations. A communications network could not, of 

 course, be set up until the sites of the Baker-Nmin camera stations 

 and of the Moon watch teams had been determined. 



During the period of the first IGY grant. Prof. Leland Cunning- 

 ham of the University of California at Berkeley was employed as a 

 consultant. He spent a good part of the summer of 1956 in Cam- 

 bridge developing a theory to deal with perturbations of the satellite's 

 orbit caused by the earth's gravity. This he was able to do with 

 considerable success, and later one of the primary responsibilities of 

 the computations section of the Observatory would be to program 

 his theory for orbital calculations on the IBM-704 electronic com- 

 puter. Also, Robert Davis made several preliminary studies of the 

 perturbations that would occur in the orbit of a satellite. 



DEVELOPMENT OF OBJECTIVES FOR USE OF DATA 



Much thought was being given to the scientific uses that could be 

 made of the Moon watch and Baker-Nunn observations. There gradu- 

 ally evolved an understanding of how these data could later provide 

 the basis for a more detailed and more precise knowledge of: 



1. The effects on the earth and the ionosphere of solar ultraviolet 

 light, cosmic and solar X-rays, and other radiations. 



2. The physics of the upper atmosphere as it related to more ac- 

 curate long- and short-range weather forecasting. 



3. The points in the upper atmosphere at which energy is either 

 absorbed or radiated, and the problem of energy balance and dy- 

 namics of the upper atmosphere. 



4. The disturbances in the atmosphere that result from solar flares 

 and solar radiation. 



5. The relation between conditions in the upper atmosphere and 

 the weather at lower levels. 



6. The variations of density and temperature at different levels of 

 the upper atmosphere. 



7. The nature and cause of the aurora. 



8. The forces that produce the changes and fluctuations in the earth's 

 magnetic field. 



9. The variations in composition and thickness of the earth's crust. 



10. The size and exact shape of the earth. 



11. The sizes and relative positions of the land masses of the earth. 

 These objectives were to become the responsibility of the research 



and analysis section of the Observatory, a unit established late in 1957. 



