Design fabricate and test instrumentation for rocketborne measurements of vehicle charging

Instrumentation for the measurement of vehicle charging was designed, fabricated, tested and integrated into an Astrobee F Rocket Payload. The vehicle was stimulated with an electron beam ejection system and a positive ion beam system, automatically programmed for sequential beam ejection in twelve modes of operation lasting one-half second each. The vehicle potential measurements were made with a dual retarding potential analyzer system, four thermal emissive passive probes mounted on booms and an inter-segment bipolar voltmeter with peak detectors and sample-and-hold amplifiers looking for large transients at the mode changes. A camera was employed to view corona discharges along the exterior surface of the payload as well as view any discharges between isolated sections of the payload. All instruments and camera were programmed along with the particle guns for optimum parameters during each part of the program cycle. A PCM telemetry format was used to accommodate 90 channels of instrument data.