Abstract. The Mars Odyssey Gamma-Ray Spectrometer is a suite of three different instruments, a gamma subsystem (GS), a neutron spectrometer, and a high-energy neutron detector, working together to collect data that will permit the mapping of elemental concentrations on the surface of Mars. The instruments are complimentary in that the neutron instruments have greater sensitivity to low amounts of hydrogen, but their signals saturate as the hydrogen content gets high. The hydrogen signal in the GS, on the other hand, does not saturate at high hydrogen contents and is sensitive to small differences in hydrogen content even when hydrogen is very abundant. The hydrogen signal in the neutron instruments and the GS have a different dependence on depth, and thus by combining both data sets we can infer not only the amount of hydrogen, but constrain its distribution with depth. In addition to hydrogen, the GS determines the abundances of several other elements. The instruments, the basis of the technique, and the data processing requirements are described as are some expected applications of the data to scientific problems.

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The OSIRIS-REx Camera Suite (OCAMS) will acquire images essential to collecting a sample from the surface of Bennu. During proximity operations, these images will document the presence of satellites and plumes, record spin state, enable an accurate model of the asteroid's shape, and identify any surface hazards. They will confirm the presence of sampleable regolith on the surface, observe the sampling event itself, and image the sample head in order to verify its readiness to be stowed. They will document Bennu's history as an example of early solar system material, as a microgravity body with a planetesimal size- scale, and as a carbonaceous object. OCAMS is fitted with three cameras. The MapCam will record color images of Bennu as a point source on approach to the asteroid in order to connect Bennu's ground-based point-source observational record to later higher-resolution surface spectral imaging. The SamCam will document the sample site before, during, and after it is disturbed by the sample mechanism. The PolyCam, using its focus mechanism, will observe the sample site at sub-centimeter resolutions, revealing surface texture and morphology. While their imaging requirements divide naturally between the three cameras, they preserve a strong degree of functional overlap. OCAMS and the other spacecraft instruments will allow the OSIRIS-REx mission to collect a sample from a microgravity body on the same visit during which it was first optically acquired from long range, a useful capability as humanity reaches out to explore near-Earth, Main-Belt and Jupiter Trojan asteroids.

Switchgrass (Panicum virgatum) is a native, perennial warm-season grass commonly used as summer pasture. Three strains of switchgrass with different in vitro DM disappearance (IVDMD) values were evaluated with yearling cattle (Bos taurus) in three replicated grazing trials All strains were similar in genetic background, maturity and yield potential. 'Trailblazer' (high-IVDMD) resulted in higher (P < .05) ADG than 'Pathfinder' and 'low-IVDMD'. Available forage of Trailblazer had higher IVDMD than Pathfinder and low-IVDMD. The IVDMD differences among strains were similar throughout the season; IVDMD declined between .3 and .5 percentage units per day. Forage availability, CP, NDF and ADF, permanganate lignin and ash were similar among strains. This study documents that plant breeders can select switchgrass plants for higher IVDMD and that strains consisting of progeny of these plants can result in higher animal gains than strains cons.isting of progeny of unselected or lowqVDMD plants with similar genetic background, forage yield, maturity, morphology and chemical composition.

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