Cadfiss test system computation and data flow integrated subsystem tests

Project Mercury was the first space program to create a real time computer-centered, worldwide satellite tracking and communications network. This network is a complex of remote sites or stations having a direct, on-demand access to the Goddard Space Flight Center (GSFC) computers via various transmission linkages: teletype, submarine cable, land lines, etc. Distance between a given site and these computers ranges from less than one thousand miles on the one hand to worldwide proportions on the other. With such an extensive network, a quick and accurate method to determine network capability to provide mission support had to be developed. Such a method had to provide for the quick identification and isolation of any malfunction anywhere in the network. In addition, a -and-ldquo;test standard-and-rdquo; applicable to all sites was needed regardless of their individual equipment configuration. Thus, a status of -and-ldquo;Good-and-rdquo; at the Canary Islands had to be identical with a status of -and-ldquo;Good-and-rdquo; at Woomera, Australia. Another factor to be considered was the tendency of electronic equipment to drift off calibration after being peaked for support of a mission. This tendency required that the peaking and the means of status determination of the equipment for support of a mission had to be performed reasonably close to llftoff. To fulfill these requirements, CADFIST, a computer-controlled, automated, network test was designed. It is a real time tracking network status check which simultaneously tests the major subsystem at each of the world-wide sites for their ability and readiness to support manned missions. CADFIST is an abbreviation for Computation and Data Flow Integrated Subsystem Test. The system, made up of individual tests under control of a master program, is designed to provide a qualitative measure of how well certain logical subsets of the over all network are functioning. Without CADFISS testing, this network verification would have to be accomplished by a personor persons centrally located making visual and voice checks.