The combined MSI-NIS investigation on NEAR consists of a Multi-Spectral Imager (MSI) and a Near-Infrared Spectrometer (NIS). MSI covers the spectral range from 0.4 to 1.1 μm in seven narrow passbands and one broad filter. MSI has a field of view of 2.25¿ by 2.90¿ and will achieve an image scale of about 3 m/pixel at the surface of Eros. NIS covers the spectral interval from 0.8 to 2.6 μm: the range between 0.804 and 1.506 μm is measured by a 32-element Germanium detector; a 32-element. Indium-Gallium-Arsenide detector observes wavelengths between 1.348 and 2.600 μm. The instrument has a selectable field of view of either 0.38¿¿0.76¿ or 0.76¿¿0.76¿. A spatial resolution of about 300 m (100 times coarser than MSI) can be achieved at Eros. A major goal of the MSI-NIS investigation is to determine the fundamental global properties of Eros; including spin state, size, and shape. Precise size and shape measurements are necessary to determine an accurate volume and thereby a mean density from mass measurements. MSI-NIS spectral data will be combined with abundance determinations of key rock-forming elements obtained by the X ray/gamma ray spectrometers (XGRS) to infer the distribution of minerals on Eros and constrain models of the asteroid's geochemical evolution. On approach to Eros, a search will be made for satellites: objects as small as 12 m (some 100 times smaller than Ida's Dactyl) could be detected.¿ 1997 American Geophysical Union