Airborne hyperspectral data have been available to researchers since the early 1980s and their use for geologic applications is well established. The launch of NASA's EO-1 Hyperion sensor in November 2000 marked the establishment of a test bed for spaceborne hyperspectral capabilities. Hyperion covers the 0.4 to 2.5 mum micrometer range with 242 spectral bands at approximately 10nm spectral resolution and 30m spatial resolution. Initial Hyperion analysis results for a site at Cuprite, Nevada, with established ground truth and years of airborne hyperspectral data show that Hyperion is performing to specifications and that data from the SWIR spectrometer can be used to produce useful geologic (mineralogic) information. Minerals mapped at Cuprite include kaolinite, alunite, buddingtonite, calcite, muscovite, and hydrothermal silica. Hyperion data collected at other sites under optimum conditions (summer season, bright targets) allow subtle distinctions such as determining the difference between calcite and dolomite and mapping spectral differences in micas caused by substitution in octahedral molecular sites. Comparison of airborne hyperspectral data (AVIRIS) to the Hyperion data establishes that Hyperion provides similar information content, with the principal limitations being reduced spatial distinctions caused by the 30m spatial resolution and limited mapping of fine spectral detail based on lower signal-to-noise ratios.