GOALS&OBJECTIVES: THE OBJECTIVES OF THIS WORK ARE TO ENHANCE THE SCIENTIFIC RETURN OF THE DAWN MISSION AT VESTA BY CREATING AND EVALUATING GLOBAL MODAL MINERALOGY MAPS OF VESTA. THE EXPECTED PRODUCTS WILL BE QUANTITATIVE MINERAL MAPS OF THE SURFACE OF VESTA AND AN IMPROVED UNDERSTANDING OF HOW MINERALOGICAL CHANGES ON THE SURFACE RELATE TO HED METEORITE COMPOSITIONS. INITIAL STUDIES OF DAWN VISIBLE INFRARED SPECTROMETER (VIR) DATA HAVE FOCUSED ON QUALITATIVE COMPARISONS OF SPECTRAL FEATURES TO THOSE OBSERVED IN LAB DATA OF HOWARDITE EUCRITE AND DIOGENITE (HED) METEORITES RESULTING IN ESTIMATES OF THE DISTRIBUTION OF THESE METEORITE COMPONENTS ON VESTA S SURFACE. HOWEVER SIGNIFICANTLY MORE INFORMATION CAN BE GAINED IF QUANTITATIVE MINERAL ABUNDANCES CAN BE DERIVED FROM SUCH DATA ESPECIALLY AT A GLOBAL SCALE. MODAL MINERALOGY AND KNOWLEDGE OF VARIATIONS IN PYROXENE CHEMISTRY FOR INSTANCE CAN BE USEFUL FOR ASSESSING VARIATIONS IN EUCRITE AND DIOGENITE COMPONENT ABUNDANCES WITHIN REGIONS WHOSE SPECTRA ARE HOWARDITE-LIKE . IN ADDITION DETAILED MIXING MODELS THAT YIELD ACCURATE MODAL MINERALOGY CAN HELP TO IDENTIFY AREAS THAT MAY INDICATE LOWER CRUSTAL OR MANTLE COMPOSITIONS REVEALING NEW INFORMATION ABOUT LITHOLOGIC VARIATIONS WITH DEPTH. THE MAJOR GOAL OF THIS WORK WILL BE TO PRODUCE GLOBAL MAPS OF MINERAL ABUNDANCES DERIVED FROM HAPKE AND SHKURATOV MODELS AS APPLIED TO VIR DATA AND TO DISCUSS THE IMPLICATIONS OF OBSERVED VARIATIONS IN MINERALOGY IN THE CONTEXT OF HED COMPOSITIONS AND PETROLOGIC EVOLUTION MODELS FOR VESTA. METHODS: THESE GOALS WILL BE ACCOMPLISHED BY APPLYING RADIATIVE TRANSFER MODELS (RTMS) TO DAWN VIR DATA. A PILOT STUDY HAS BEEN CONDUCTED TO VALIDATE OUR METHODS AND DEMONSTRATE OUR ABILITY TO WORK WITH VIR DATA. TO FURTHER TEST THE VALIDITY OF HAPKE AND SHKURATOV RTMS FOR HED AND DAWN SPECTRA WE WILL FIRST CARRY OUT ADDITIONAL LAB MEASUREMENTS OF HOWARDITE SAMPLES TO EXPAND UPON OUR EXISTING TEST DATASET THAT RELIED UPON DIOGENITE AND EUCRITE SAMPLES. THOUGH A MINOR COMPONENT THIS INITIAL LAB WORK WILL PROVIDE A MUCH-NEEDED FOUNDATION FOR QUANTIFYING THE UNCERTAINTIES ASSOCIATED WITH APPLYING RTMS TO VIR SPECTRA AN IMPORTANT STEP GIVEN THAT BRECCIAS LIKELY DOMINATE VESTA S SURFACE. SAMPLES WILL BE CHARACTERIZED BY VIS-NIR REFLECTANCE SPECTROSCOPY AND MODAL MINERALOGY WILL BE ESTIMATED FROM XRD DATA USING RIETVELD REFINEMENT. THE BULK OF THE WORK WILL INVOLVE ANALYSIS OF DAWN DATA AND APPLICATION OF THE HAPKE AND SHKURATOV RTMS TO VIR SPECTRA USING INVERSE THEORY. ISIS SOFTWARE WILL BE USED TO PROCESS THE VIR DATA MAP PROJECT IMAGES AND MOSAIC INDIVIDUAL IMAGE CUBES. MATLAB SCRIPTS WILL BE USED TO APPLY OUR RTM CODES TO THE VIR DATA RESULTING IN MODAL MINERALOGY MAPS (E.G. MAPS OF OLIVINE PYROXENE PLAGIOCLASE ABUNDANCE ETC.). THE RESULTING MAPS AND SPECTRA WILL THEN BE COMPARED TO HED SPECTRA AND COMPOSITIONS TO ASSESS DIFFERENT PETROLOGIC MODELS. DAWN FRAMING CAMERA DATA WILL BE EXAMINED FOR AREAS OF SPECIAL INTEREST (E.G. HIGH OLIVINE AND/OR HIGH PYROXENE CONCENTRATIONS) TO BETTER UNDERSTAND THE LOCAL GEOLOGIC CONTEXT OF THESE REGIONS. RELEVANCE: THIS WORK IS RELEVANT TO THE DDAP CALL IN THAT IT WILL ENHANCE THE SCIENTIFIC RETURN OF THE DAWN AT VESTA MISSION THROUGH THE PROCESSING AND ANALYSIS OF EXISTING DAWN VIR DATA TO PRODUCE QUANTITATIVE MINERAL MAPS OF VESTA S SURFACE. THESE MINERAL MAPS WILL BE COMPARED AGAINST SPECTRAL AND MINERALOGICAL COMPOSITIONS OF HED METEORITES TO TEST VARIOUS MODELS ABOUT THE PETROLOGIC EVOLUTION OF VESTA WITH AN EMPHASIS ON THE ABUNDANCE OF EUCRITE AND DIOGENITE COMPONENTS IN REGIONS THAT ARE SPECTRALLY AKIN TO HOWARDITES. THE MAPS RESULTING FROM THIS WORK WILL BE ARCHIVED IN THE PDS FOR USE BY THE BROADER COMMUNITY.