INTERACTION OF AN EXPANDING PLASMA CLOUD WITH A SIMPLE ANTENNA - APPLICATION TO ANOMALOUS VOLTAGE SIGNALS OBSERVED BY VOYAGER-1, VOYAGER-2,ICE, AND VEGA SPACECRAFT

High-velocity impacts of interplanetary dust grains with spacecraft ca n give rise to transient plasma clouds from the spacecraft bodies. It is believed these plasma clouds can affect spacecraft instruments. Lab oratory results are presented demonstrating the interaction of small e xpanding plasma clouds with a simple antenna. Results corroborate the hypothesized origin of anomalous impulsive voltage signals recorded by Voyager 1 and 2 spacecraft during flybys of Saturn, Uranus, and Neptu ne, the International Cometary Explorer (ICE) during its flyby of come t Giacobini-Zinner, and Vega during its flyby of comet Halley. Results suggest that preflight calibration of antenna-plasma interactions may extend the range of spacecraft diagnostics.