We want to perform isotope analyses of near Earth asteroid 25143 Itokawa silicate grains using the NanoSIMS 50L secondary ion mass spectrometer at Arizona State University (ASU). The isotope systems that will be investigated include H as well as spallation nuclides Li and B. We propose to study Itokawa olivine, pyroxene, and plagioclase grains that are already mounted as slabs in epoxy. The H isotope compositions and water content of Itokawa material is unknown and this study can reveal how ‘wet’ Itokawa is, and what its H isotopic composition is relative to other planetary bodies in the solar system. The spallation nuclides Li and B are a measure of particle irradiation via galactic cosmic rays or solar energetic particles. We wish to reassess these isotopic systems in olivines and measure them in pyroxenes for the first time with matrix-matched implant standards. A recent Fujiya et al. (2016) study reports B isotope ratios and abundances in olivine grains do not use matrix-matched standards. The proposed NanoSIMS measurements aim to study the volatile content of the Itokawa surface in order to understand both the fundamental surface processes on an airless body and the evolutionary history of the high-temperature minerals. The questions in this proposal can only be answered by studying samples from Itokawa, and can provide valuable insight about small S-type ‘rubble-pile’ asteroids with similar reflectance spectra.