Automated microwave testing of spacecraft

Preflight evaluation of the performance of the communications subsystem of communications satellites is a rigorous and demanding task. It involves exposing the spacecraft to predicted environments while interspersing performance measurements that evaluate subsystem performance. The International Business Service (IBS) version of the Intelsat VA satellite has more than 1500 different pathways that can be utilised to relay a microwave signal through the satellite. The large number of pathways to be tested adds another degree of complexity to the test programme and creates a critical need for high-speed automated testing. These requirements affected the evolution of the latest generation of microwave automatic test equipment (MATE) in several areas: closed-loop path configuration, user-friendly operator interface, multitasking capability, equipment and peripheral selection, self-test capability, microprocessor-based custom peripherals, and development/reconfiguration cost. The test measurement requirements and the techniques used to implement them are discussed. The requirements have been cost-effectively satisfied in a system that has the flexibility to handle spacecraft requirements. In addition to providing highspeed automated testing, data analysis and display, the system allows for quick reconfiguration and test method restructuring when required for investigation of anomalous performance or introduction of special tests.