Although the effect of zero or low g environments on the development of microstructure and properties of engineering materials is of significant theoretical and practical interest, additive manufacturing technologies that are relatively unaffected by the gravitational environment will be of use for space based construction applications. Specifically, solid state processes in which confinement of high temperature molten materials does not present engineering difficulties may be of utility. Ultrasonic Consolidation is one such process. UC is a direct metal additive manufacturing technology suitable for use with a range of metals including Al, Mg, Ti and Ni based alloys among others. Ultrasonic energy is used to produce true metallurgical bonds in the solid state between previously deposited material and incremental material volumes. The fundamentals of the UC process, its current applications and potential for use in zero g environments are discussed.