This paper describes the history, functions, and usage of the program that was used to analyze the plans for direct broadcast satellite service developed in the course of the 1983 Regional Administrative Radio Conference for ITU Region 2. Given the requirements for direct broadcast service by the administrations, the conference delegates 1) developed the appropriate technical parameters; 2) made tentative assignments to the orbit locations, frequencies, and polarizations of space stations; 3) calculated the interferences and margins of such assignments through the use of the Spectrum Orbit Utilization Program (SOUP); and 4) iterated this procedure until an acceptable plan was found.