THE MAIN SCIENCE GOAL OF THE PROPOSED INVESTIGATION IS TO MAP THE SURFACE COMPOSITION (E.G. MINERALS/METEORITE TYPES AND THEIR ABUNDANCES) OF BENNU IN AN EFFORT TO (1) BETTER UNDERSTAND ITS FORMATION (2) SELECT A SAMPLING SITE THAT MAXIMIZES THE SCIENCE RETURN OF THE SAMPLE (3) PLACE THE SAMPLING SITE IN GEOLOGIC CONTEXT WITH THE REST OF THE ASTEROID AND (4) PLACE BENNU IN THE CONTEXT OF OTHER NEAR-EARTH ASTEROID AND MAIN BELT ASTEROIDS. THIS GOAL WILL BE ACHIEVED BY INTEGRATING OBSERVATIONS MADE ACROSS VISIBLE TO NEAR INFRARED AND THERMAL INFRARED WAVELENGTHS WITH LABORATORY MEASUREMENTS OF BENNU ANALOGUES. THE STRENGTH OF VISIBLE TO NEAR INFRARED (VNIR) REFLECTANCE IS THE ABILITY TO DETECT THE PRESENCE OF FE-BEARING ANHYDROUS SILICATES HYDRATED SILICATES CARBONATES ORGANICS ETC. [E.G. BURNS 1970]. WHILE THE VNIR CAN BE USED TO EASILY IDENTIFY SPECTRALLY DOMINANT MINERAL PHASES ESTIMATING MINERAL ABUNDANCES IS MORE COMPLICATED DUE TO INTIMATE MIXING AT THESE WAVELENGTHS. ONE OF THE MAIN STRENGTHS OF THERMAL INFRARED (TIR) SPECTROSCOPY IS THE ABILITY TO ESTIMATE MINERAL ABUNDANCES DUE TO SURFACE SCATTERING AT THESE WAVELENGTHS [E.G. RAMSEY AND CHRISTENSEN 1998]. HOWEVER THE NATURE OF SCATTERING AT TIR WAVELENGTHS CAN BECOME COMPLICATED AS SAMPLE ALBEDO PARTICLE SIZE POROSITY AND ENVIRONMENTAL CONDITIONS CAN AFFECT PORTIONS OF TIR SPECTRA [E.G. LOGAN ET AL. 1973; SALISBURY AND WALD 1992; THOMAS ET AL. 2014; DONALDSON HANNA ET AL. 2017]. THUS AN ANALYSIS THAT COMBINES THE STRENGTHS OF BOTH SPECTRAL RANGES AND COMBINES SPACECRAFT OBSERVATIONS WITH LABORATORY WORK WILL PROVIDE A MORE ROBUST UNDERSTANDING OF BENNU S SURFACE COMPOSITION. IN THE PROPOSED INVESTIGATION SPACECRAFT OBSERVATIONS FROM THE OSIRIS-REX CAMERA SUITE (OCAMS) MAPPING CAMERA (MAPCAM) VISIBLE IR SPECTROMETER (OVIRS) AND THERMAL EMISSION SPECTROMETER (OTES) AS WELL AS LABORATORY MEASUREMENTS WILL BE INTEGRATED TO PLACE CONSTRAINTS ON BENNU S SURFACE MINERALOGY. IN PARTICULAR LABORATORY MEASUREMENTS OF BENNU ANALOGUES (E.G. TERRESTRIAL MINERALS MINERAL MIXTURES AND CARBONACEOUS CHONDRITE METEORITES) WILL BE MEASURED WITH A RANGE OF SAMPLE ALBEDO PARTICLE SIZE POROSITY AND ENVIRONMENTAL CONDITION (E.G. ATMOSPHERIC PRESSURE AND INCIDENT SOLAR-LIKE IRRADIATION) TO CONSTRAIN THEIR EFFECTS ON THE RESULTING TIR SPECTRA. THESE MEASURED SPECTRAL EFFECTS ALONG WITH MINERAL IDENTIFICATIONS FROM OVIRS SPECTRA WILL SERVE AS INITIAL CONSTRAINTS IN A LINEAR UNMIXING ALGORITHM THAT WILL BE USED TO ESTIMATE MINERAL ABUNDANCES FROM OBSERVED OTES SPECTRA. ESTIMATING THE UNCERTAINTIES IN THE DERIVED MINERAL ABUNDANCES DUE TO ALBEDO PARTICLE SIZE POROSITY AND ENVIRONMENTAL CONDITION ARE IMPORTANT FOR UNDERSTANDING THE QUALITY OF THE LINEAR UNMIXING ALGORITHM RESULTS. RELEVANCE TO THE OSIRIS-REX PARTICIPATING SCIENTIST PROGRAM (PSP): THIS INVESTIGATION IS DIRECTLY RELEVANT TO THE PSP AS IT INVOLVES THE ANALYSIS OF REMOTE SENSING OBSERVATIONS OBTAINED FROM OVIRS AND OTES AND BY INTEGRATING THESE DATA ALONG WITH LABORATORY MEASUREMENTS OF BENNU ANALOGUES TO ADDRESS FUNDAMENTAL SCIENCE QUESTIONS REGARDING BENNU S FORMATION ENHANCING THEIR SCIENTIFIC RETURNS. IN THE PROPOSED INVESTIGATION TO BETTER UNDERSTAND THE FORMATION AND EVOLUTION OF BENNU WE ADDRESS TWO OF THE HIGH PRIORITY AREAS OF RESEARCH INCLUDING THE IDENTIFICATION AND CHARACTERIZATION OF (1) SURFACE MINERALOGY AS A FUNCTION OF LOCATION AND GEOLOGIC CONTEXT AND (2) POTENTIAL SAMPLING SITES OF HIGH SCIENCE RETURN.