New generation of micro-scale sample-processing instruments for future exploration of Mars and Near Earth Objects (NEO)

The prospect of finding chemical signatures of present or past life on Mars and NEO is one of the important drivers behind NASA’s Mars Exploration Program (MEP) and Comet and Asteroid New Frontiers missions. One of the technical challenges facing MEP and NEO missions is the lack of compact sample-processing technology that enables extensive cataloging of organic and inorganic molecules and ions in crustal materials. In the past two years, we have been developing a super-compact, lightweight and low power-consumption micro-extractor (μEX) instrument that will address this challenge for in situ Mars exploration missions, Mars Sample Return sample analysis, and cometary and asteroidal material chemical characterization. The core operational principle of μEX is based on a unique property of water - the ability to change its permittivity (i.e., dielectric constant) as a function of frequency to match the dielectric constants of organic solvents. In our instrument, the dielectric constant of water decreases when RF radiation (180, 90, and 60 GHz) interacts with translational modes in a solution by disrupting orientation of the water molecules’ individual molecular dipoles. Since “like dissolves like”, μEX can then extract biomarkers from soil samples by simply applying radiation to water, without the use of any other chemicals. Consequently, target biomarkers that are characterized by very different properties (e.g., size, charge, volatility, polarity, etc.), and which are typically only soluble in organic solvents, can now be easily extractable from the solid matrices and soluble in water. Here we present our research results, which include characterization of μEX operation, sample injection into μEX as a function of mineral composition, flow rates and sample densities, and data on target compounds extracted from planetary-analog soil samples.