For a space-based fabrication effort to be effective, the weight, power requirements and footprint must be minimized. Because of the unique beam forming properties at the millimeter-wave frequency of 83 GHz, a compact and efficient materials heating system can be devised that can satisfy this need. To date, microwave and millimeter-wave based systems for materials processing have been developed only for terrestrially based manufacturing operations. The purpose of this SBIR proposal is to begin the development and to perform proof-of-concept tasks to demonstrate the feasibility of the microwave approach to space-based materials processing. Current conventional heating technology requires the heating of the complete volume of the furnace in order to achieve the temperatures necessary to perform a fabrication activity. This is typically a slow and energy intensive process. At 83 GHz, technology is available that can focus a multi-kilowatt beam into an area of 4 cm2 or smaller. Based upon the absorptive capability of the material, this may result in a temperature rise of several hundred degC/min which is confined to the immediate area of beam impingement. The result is one of putting the energy where it is needed to perform the task (e.g., ceramic joining, glass melting) more effectively.