This proposal details a plan to investigate the evolutionary history of surface materials from 25143 Itokawa, the Hayabusa samples. Our studies are based on the measurement of those nuclides produced in asteroidal surface materials by cosmic rays. Cosmic-ray-produced (cosmogenic) radionuclides are used to determine the duration and nature of the exposure of materials to energetic particles. Our goals are to understand both the fundamental processes on the asteroidal surface and the evolutionary history of its surface materials. These processes occur over timescales spanning the present to 107 yrs into the past. They are also key to understanding the history of Itokawa’s surface and asteroid- meteoroid evolutionary dynamics. To achieve our key goals, in particular reconstructing the evolutionary histories of the asteroidal surface, we propose (1) characterizing each particle using SXCT, SXRD, and FE-SEM without modification of the sample, (2) embedding each particle in acrylic resin and slicing a small corner with an ultra-microtome in order to minimize sample loss. Examining the ultra-thin section and the exposed surface by super-STEM, VEELS, EBSD, and SIMS for characterizing surface morphology, space weathering, quantitative microstructure, and oxygen three-isotope analysis, and finally (3) measuring small amounts of cosmogenic radionuclides (104-105 atoms) in Hayabusa samples by AMS. To accomplish these goals we request three large Hayabusa samples that have never been mounted in Epoxy resin.