Description: Composite Overwrapped Pressure Vessels (COPVs) are used for storing pressurized gases on board spacecraft when mass saving is a key requirement. All future mass critical space applications will be designed to use COPVs to minimize vehicle mass. Saving mass is critical for facilitating deep space travel in which a series of space depots will be implemented as a means of providing fuel along the journey. These depots will require a means for long-term storage of fuel and other resources that can be placed in the appropriate locations ahead of time. Metal Matrix Composite (MMC) materials offer tremendous potential for lightweight propellant and pressurant tankage. Touchstone teamed with Carleton Technologies Inc. (a subsidiary of Cobham) to demonstrate feasibility of this technology in Phase I. A COPV with Al MMC liner was designed and a demonstration liner was produced. The proposed Phase II effort will address key technical risk items identified in Phase I, optimize the liner design and process, and extend the Technology Readiness Level to 5 by completing validation testing on a full-scale COPV demonstration article.

Benefits: This innovative technology will be useful in a broad spectrum of commercial applications wherever strength-to-weight performance is crucial, especially at elevated and/or cryogenic temperatures. Specific applications in the automotive market sector include selectively reinforced aluminum and magnesium castings, flywheels for hybrid vehicles, liners for lightweight composite tanks used on alternative fuel vehicles, and other types of storage tanks. This technology could also make its way into the sporting goods market incorporated into golf club shafts, tennis rackets, and bicycle frames. Touchstone has conducted preliminary discussions with True Temper Sports, the world's largest manufacturer of golf shafts. The proposed work will move the technology closer to a point to be tailored to meet the technical and manufacturing requirements for golf club shafts.

The proposed project will provide advanced development of a new MMC technology for specific application to lightweight storage of pressurants for chemical propulsion systems. This same processing technology could help overcome technical hurdles in the areas of lightweight cryogenic tanks, ducting, and payload bays for space vehicles. Other applications include fairings, intertank structures, and truss members for both reusable and expendable launch vehicles. The Mechanics and Durability Branch at NASA Langley has also expressed interest in using the MMC prepreg tape technology in advanced aerodynamic and structures technologies for subsonic transport air vehicles, specifically for selectively reinforcing aircraft skins to obtain aeroelastic tailorability. Other aircraft structures such as stiffeners, wing skins, and wing spar caps could also be manufactured out of MetPreg.