Rover-mounted Hydrated Mineral Detector for Mars Exploration: A Preliminary Report

The rover-mounted hydrated mineral detector (HMD) is based on a dielectric spectrometer (tuned frequency range of 0.8-4 MHz) that will detect bulk subsurface hydrated minerals in local scale. The HMD is a compact, low-mass (1.5 kg), and low-power instrument (5 W) suitable for Mars application. Compared with orbiter-based instruments with low horizontal resolution (5-10 km), the HMD will offer high resolution (2 m) that can identify optimal sampling sites for the presence of hydrated minerals. From field testing with reduced radio frequency (RF) power (P (rf) = 10 mW), the HMD demonstrated detection of shallow buried gypsum samples. When developed with full RF power, the HMD could potentially detect hydrates down to depths of 2 m (P (rf) = 1 W) or 4 m (P (rf) = 36 W) in Martian soil. Unlike conventional dielectric spectrometers, which require small amounts of the sample (5-10 g) to be placed inside sample cells, the HMD will detect hydrated minerals by scanning over the Mars surface mounted on a rover platform (<1 m above ground) without any sample preparation. This capability will allow future rovers to rapidly assess the scientific potential of field sites. Compared with optical techniques that are limited to surface exposed mineralogical features that could be obscured by dust and weathering products, the HMD will detect bulk subsurface hydrated minerals along the rover traverse irrespective of surface obscuration. The HMD (TRL 4) is a proof-of-concept instrument that can be developed and matured for future Mars rover missions.