This article outlines how projection x-ray microscopy can be used to view the structures that develop within solidifying metals during the freezing process (in real-time and in situ), A description of x-ray microscopy methods will be given. The specialized furnace design and techniques required to permit observation of solidification phenomena will also be described. This forms the outline of the salient features of our X-ray Transmission Microscope (XTM) for solidification studies. This instrument is being developed for microgravity materials research at NASA's Space Science Laborataory in the Marshall Space Flight Center, Alabama. Finally, a sampling of radiomicrographs taken during alloy solidification will be presented.