Dielectric Properties of Martian Soil Simulant

摘要

NASA's Viking and Mars Pathfinder missions each used onboard instruments to determine the composition of the Martian soil at their respective landing sites. Those findings led to the development of a Martian sbil simulant (JSC Mars-1) at NASA Johnson Space Center. However, in spite of the compositional studies conducted during those previous missions, no direct measurements were ever made of the dielectric properties of the Martian soil. Recently, instrumentation was developed at NASA Kennedy Space Center that enables investigations of the dielectric properties of granular materials to be conducted, including studies of Martian soil simulant. In the present study, a three-electrode system was used to measure the frequency response to an applied sinusoidal voltage of finely ground Martian soil simulant that was placed in a dry, low-vacuum environment. The data is shown to support a simple model of the granular system in which the resistances and capacitances of individual particles are connected in series by the resistance and capacitance of interparticle contacts.