Changing operational requirements within the Navy defines the need for lighter, faster ships with increased range and payload. To achieve these requirements the Navy is investing in new hull forms and aluminum alloys for the Littoral Combat Ship (LCS), the Landing Helicopter Assault (Replacement) Ship, and the Joint High Speed Vessel. Friction stir welding (FSW) has proven to be a viable means for joining aluminum during the vessel manufacturing process for LCS, and is a likely joining process for other high speed aluminum vessels. While producing welds of high quality, FSW is characterized by high equipment costs and lack of field repair methods. This report outlines a U.S. Navy-Wichita State University research effort to develop high rotational speed – friction stir welding (HRS-FSW), a process that offers the potential for significant reductions in the size, mass, and cost of FSW systems for both assembly and repair (conventional and/or ―in-situ‖) welding.