SHERLOC: Scanning Habitable Environments With Raman & Luminescence for Organics & Chemicals, an Investigation for 2020

Tuesday, 16 December 2014: 5:15 PM
Luther W Beegle1, Rohit Bhartia2, Lauren P DeFlores3, Sandy A Asher4, Aaron S Burton5, Samuel M Clegg6, Pamela Gales Conrad7, Kenneth S Edgett8, Bethany L Ehlmann9, Falko Langenhorst10, Marc Fries5, Kenneth H Nealson11, Jürgen Popp12, Pablo Sobron13, Andrew Steele14, Roger C Wiens15 and Kenneth H Williford3, (1)JPL, Pasadena, CA, United States, (2)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (3)Jet Propulsion Laboratory, Pasadena, CA, United States, (4)University of Pittsburgh Pittsburgh Campus, Pittsburgh, PA, United States, (5)NASA Johnson Space Center, Houston, TX, United States, (6)Los Alamos National Laboratory, Los Alamos, NM, United States, (7)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (8)Malin Space Science Systems, San Diego, CA, United States, (9)California Institute of Technology, Pasadena, CA, United States, (10)Friedrich Schiller University of Jena, Jena, Germany, (11)University of Southern California, Los Angeles, CA, United States, (12)Friedrich-Schiller University, Institute for Physical Chemistry & Abbe School of Photonics, Jena, Germany, (13)SETI Institute Mountain View, St. Louis, MO, United States, (14)Carnegie Institution for Science, Washington, DC, United States, (15)Space Science and Applications, Los Alamos, NM, United States
The Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals SHERLOC investigation was recently selected for the Mars 2020 integrated payload. SHERLOC enables non-contact, spatially resolved, and highly sensitivity detection and characterization of organics and minerals in the Martian surface and near subsurface. SHERLOC is an arm-mounted, Deep UV (DUV) resonance Raman and fluorescence spectrometer utilizing a 248.6-nm DUV laser and 50 micron spot size. The laser is integrated to an autofocusing/scanning optical system, and co-boresighted to a context imager with a spatial resolution of 30 µm. SHERLOC operates over a 7 × 7 mm area through use of an internal scanning mirror. The 500 micron depth of view in conjunction with the MAHLI heritage autofocus mechanisms enables arm placements from 48 ±12.5 mm above natural or abraded surfaces without the need for rover arm repositioning/movement. Additionally, borehole interiors to a depth of ~25 mm, at angles from normal incidence to ±20 degrees, can be analyzed.

Deep UV induced native fluorescence is very sensitive to condensed carbon and aromatic organics, enabling detection at or below 10-6 w/w (1 ppm) at <100 µm spatial scales. SHERLOC’s deep UV resonance Raman enables detection and classification of aromatic and aliphatic organics with sensitivities of 10-2 to below 10-4 w/w at <50 µm spatial scales. In addition to organics, the deep UV Raman enables detection and classification of minerals relevant to aqueous chemistry with grain sizes below 20 µm grains.

The instrument goals are to assess past aqueous history, detect the presence and preservation of potential biosignatures, and to support selection of return samples. To do this, SHERLOC will measure CHNOPS-containing mineralogy, measure the distribution and type of organics preserved at the surface, and correlate them to textural features.