PRESOLAR GRAINS OF STARDUST ARE A TRACE CONSTITUENT OF PRIMITIVE METEORITICAL MATERIALS AND PROVIDE CRUCIAL INFORMATION ABOUT THE STARTING MATERIALS OF THE SOLAR SYSTEM THE ASTROPHYSICAL CONTEXT OF SOLAR SYSTEM FORMATION TRANSPORT AND PROCESSING OF DUST IN OUR PROTOPLANETARY DISK AND PLANETESIMAL ALTERATION DURING THE EARLIEST STAGES OF PLANET FORMATION. WE PROPOSE THREE MULTI-TECHNIQUE (NANOSIMS TEM NANOFTIR RAMAN) MICROANALYTICAL STUDIES OF PRESOLAR GRAINS IN METEORITES AND INTERPLANETARY DUST PARTICLES DESIGNED TO ADDRESS SCIENTIFIC QUESTIONS OF HIGH RELEVANCE TO THE EMERGING WORLDS PROGRAM. THE PROPOSED WORK BUILDS ON OUR STRONG PRIOR RECORD OF PRESOLAR GRAIN RESEARCH AND MUCH OF IT WILL TAKE ADVANTAGE OF A NEW NASA-FUNDED HIGH-RESOLUTION RF PLASMA NEGATIVE O ION SOURCE FOR THE CARNEGIE NANOSIMS 50L ION PROBE EXPECTED TO BE INSTALLED IN EARLY 2017. IT ALSO WILL BENEFIT FROM COLLABORATION WITH WORLD EXPERTS IN STELLAR EVOLUTION AND NUCLEOSYNTHESIS THEORY TO AID IN INTERPRETATION OF ISOTOPIC DATA. THE PROPOSED STUDIES INCLUDE: 1) ISOTOPIC (CR AND O) AND TEM CHARACTERIZATION OF 54CR RICH PRESOLAR GRAINS TO BETTER UNDERSTAND THEIR ORIGIN AND THAT OF BULK NUCLEOSYNTHETIC ISOTOPIC VARIATIONS IN PLANETARY MATERIALS. THE NEW PLASMA ION SOURCE WILL BE CRUCIAL TO IDENTIFICATION OF THESE GRAINS WHICH CAN THEN BE TARGETED FOR FURTHER ISOTOPIC AND TEM ANALYSIS. 2) ISOTOPIC MINERALOGICAL AND SPECTROSCOPIC CHARACTERIZATION OF PRESOLAR SILICATE GRAINS. THE NEW ION SOURCE WILL ENABLE ISOTOPE MEASUREMENTS OF KEY ELEMENTS (MG SI CA FE K ) THAT HAVE THUS FAR BEEN TECHNICALLY CHALLENGING OR IMPOSSIBLE. MOREOVER WE WILL USE NANOFTIR AND HIGH-RESOLUTION ELECTRON ENERGY LOSS SPECTROSCOPY TO CHARACTERIZE THE INFRARED SPECTRA OF INDIVIDUAL PRESOLAR SILICATE GRAINS IN ORDER TO PROVIDE GROUND TRUTH FOR REMOTESENSING OBSERVATIONS OF CIRCUMSTELLAR INTERSTELLAR AND COMETARY DUST. 3) ISOTOPIC AND MICROSTRUCTURAL CHARACTERIZATION OF PRESOLAR SIC GRAINS AND THEIR SUB-GRAINS IN METEORITES. WE WILL TAKE ADVANTAGE OF NEW NONDESTRUCTIVE (RAMAN AND SEM-EDS BASED) METHODS WE HAVE DEVELOPED FOR IDENTIFICATION OF RARE SUB-POPULATIONS OF SIC GRAINS. THIS WORK WILL PROVIDE GROUND-TRUTH ON THE NUCLEOSYNTHETIC PROCESSES RESPONSIBLE FOR ISOTOPIC VARIABILITY OBSERVED IN PLANETARY MATERIALS AND ON GALACTIC CHEMICAL EVOLUTION PROCESSES RESPONSIBLE FOR THE BULK SOLAR COMPOSITION AND PROVIDE NEW INSIGHTS INTO DUST CONDENSATION PROCESSES. THESE STUDIES WILL TAKE ADVANTAGE BOTH OF THE NEW O SOURCE (FOR EXAMPLE TO MEASURE TI ISOTOPES IN TINY TIC AND TIN SUBGRAINS) AND OF THE EXCITING NEW CHILI INSTRUMENT AT THE UNIVERSITY OF CHICAGO (TO MEASURE TRACE-ELEMENT ISOTOPIC COMPOSITIONS OF IMPORTANT ELEMENTS INCLUDING MO ZR BA ND FE AND NI). WE WILL ALSO EXPLORE APPLICATIONS OF A NEW ACCELERATOR-BASED SIMS INSTRUMENT RECENTLY CONSTRUCTED AT THE NAVAL RESEARCH LABORATORY.