The advancement of stir welding technologies has application well beyond NASA applications. It is envisioned this technology will become important to the Navy for ship building applications, as well as to the larger commercial ship building industry for construction of ship hulls and superstructure. The process will also be useful to fabrication of large tankage and piping for the chemical processing and transportation industry. Potential NASA applications for the TSW technologies we propose developing and implementing would be solid and liquid rocket motor casing, liquid rocket nozzle extensions, and other high temperature components; more specifically, a nozzle skirt extension for the J2X engine and 4130 steel external casing for the NASA sounding rocket. The proposed technology will enable the creation of processing maps to characterize the solid-state joining of metals by thermal stir welding. The closed-loop temperature control system (applicable to other types of stir welding) will allow higher fidelity, stir welding of alloys of interest to NASA for manufacturing space craft and heavy lift vehicles. The analytical simulation of the stir welding process will enable more rapid and less costly formation of processing maps of a given material. The control system and analytical simulation combined will enable formation of a processing map for Haynes 230 (the alloy of choice by NASA for the J2X nozzle extension) and establishment of a rapid process qualification methodology for thermal stir welded components. Keystone also recently demonstrated over 60-feet of solid-state titanium welds for evaluations and for build of a partial section of a littoral ship structure built by Litton Industries. With the success of this demonstration ONR is considering extension of the project to include further mechanical/structural testing of the hull and superstructure section. Is it this type of foundational work, enabled by the NASA TSW process, Keystone anticipates emergence into commercial ship building applications for the TSW process.