NSSDCA ID: 1964-074A-04
Mission Name: S 55CThe purpose of the experiment was to determine whether the space radiation environment had any adverse effects on the operation of the capacitor as a meteoroid-penetration detector. Observations in the laboratory indicated that energetic electrons in space might collect in the dielectric and produce false penetration counts. The instrumentation consisted essentially of two capacitors made up of a thin film polymer dielectric (bilaminate 3.8-micron thick, half-hard, type 302), which served as one electrode. A copper layer, about 0.65-micron thick, was vacuum-deposited on the outer surface of the dielectric, thus permitting it to serve as the second electrode. The capacitors were each mounted on a 0.63-cm-thick layer of polyurethane foam support by means of a 2.5-micron adhesive. The foam support, in turn, was seated in a laminated fiberglass tray that served as the mounting fixture. A penetration into the charged capacitor by a projectile caused the capacitor to be momentarily shorted and discharged. This discharge was detected and stored in a counter for later transmission. The conduction path dissipated in less than 1 microsecond and allowed the capacitor to recharge and detect any additional penetrations. Two discharges were recorded for one of the detectors during the 365-day lifetime of the experiment (November 6, 1964, to November 5, 1965). No discharges were recorded for the second capacitor. More refined laboratory tests, however, revealed that the number of radiation-induced pulses would be about the same as or less than the number resulting from actual punctures, thus making it difficult, if not impossible, to distinguish between the two. Hence, the origin of the two counts (electron or meteoroid) could not be determined. It was determined from the data, however, that any radiation-induced pulses greater than 2 V were at a minimum and would not likely affect the meteoroid flux data to any great extent, particularly when the penetration rates were relatively high.
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Name | Role | Original Affiliation | |
---|---|---|---|
Mr. James H. Siviter | Principal Investigator | NASA Langley Research Center |