The Advanced X-ray Spectroscopic Imaging Observatory (AXSIO) is a NASA facility class X-ray observatory which can carry out many of the science goals of the International X-ray Observatory as outlined in the NWNH Astro2010 Decadal Survey. Studies of the mission configuration and science reach will inform NASA technology investments over the next several years. The primary science goals will be directly observing the effects of strong gravity in black holes; mapping temperatures, abundances and dynamics in hot gas on scales ranging from the local ISM to galaxy clusters; observing feedback from AGN and star formation in galaxies; finding the missing baryonic matter; and studying the structure of neutron stars. The mission configuration required to achieve these goals builds on the IXO segmented glass optics technology, but with a (shorter)10m focal length. These optics provide 10 arcsec HPD (5 arcsec goal) images and 1m2 of area at 1.25keV and 0.2m2 at 6keV. A new micro-calorimeter configuration provides 2 eV spectral resolution over a central 0.6 arcmin area, and < 5eV over a 4.8 arcmin square extended region. A grating spectrometer provides the low-energy spectroscopy (from 0.3keV to 1.0keV) with spectral resolution of>3000 and an effective area of>1000cm2.