ASTID

Green and UV Raman Imager with Laser-induced Autofluorescence (GURILA): Next Generation Instrument for Mineral-Organic Mapping

PI: Rohit Bhartia

This proposal addresses the need for a micromapping organic and mineral detection system for in situ and sample return missions to Mars and future in-situ missions to moons, asteroids, and comets. The need for microscale mapping was recently (July 09) presented by the Mid Range Rover – Science Analysis Group (MRR-SAG) with a strawman payload that consisted of a mapping deep UV fluorescence/Raman instrument for organic detection and a mapping Raman instrument for mineralogy. As such, we propose a Green and deep-UV Raman and Laser-induced Autofluorescence (GURILA) instrument is suitable for arm mounting on the Mars 2018 – Mid Range Rover (MRR). The instrument leverages off of SBIR/STTR funding for deep UV (DUV) fluorescence and Raman marker band instruments as well as heritage and lessons learned from the green Mars Microbeam Raman Spectrometer (MMRS) instrument development. The resulting micro-mapping instrument combines deep UV (DUV) Raman/fluorescence spectroscopy to enable imaging of organics, at sub-parts-per-billion sensitivity, with green Raman spectroscopy for comprehensive mineralogy; enabling spatially correlated organic-mineral maps over 1cm2 areas at 50 to 200 um resolution without sample handling.

For ultrasensitive detection and characterization of organics, the current flight instrument gold standard is the SAM GC/MS on MSL. For definitive mineralogy, the gold standard is the CHEMIN XRD on MSL. These state-of-the-art analytical systems provide a comprehensive organic and mineral inventory of a sample. However these instruments are not well-suited for missions smaller than MSL. Additionally both require sample handling and processing and are unable to preserve the original stratigraphy of the sample. Consuming ~1/30 the power and 1/10 the mass of SAM, GURILA provides the only viable solution that preserves spatial information and also enables ultrasensitive detection and sufficient characterization of organics and minerals for in-situ exploration rovers/lander, sample cache missions, and can provide risk reduction in Sample return missions.

Deep UV fluorescence is the only known measurement technique that can provide sub-parts-billion sensitivity to organic compounds present in planetary materials, without any sample acquisition or processing. Fluorescence provides valuable scientific information in its own right by detecting aromatic ring structures of varying ring numbers and conformational arrangements When combined with deep UV Raman and green Raman capabilities GURILA will detect and map diffuse, condensed, simple and complex, organics, key chemical bonds including C-H, CN, C=O, C=C, NHx, NOx, SOx, POx, ClO4 (perchlorates), H20 (water/ice) and minerals such as clays, sulfates, nitrates silicates, carbonates and various oxides and map their distributions. Mapping the distribution of these features establishes spatial relationships that will provide critical contextual information to greatly constrain the origin of detected materials. In addition, detection of vibrational bonds between CHNOPS elements can provide an indirect assessment of the light element distribution as a complement to an APXS or other future elemental detection systems (micromapping XRF, EDAX, etc.). Together these measurements provide critical new insights to a planet’s history and habitability