Lightweight structures has enormous potential for space vehicles applications as the reduction of weight from metallic structures add to vehicle performance, reduce launching and maintenance costs. The high strength, superior stiffness, and lightweight characteristics of carbon fibers have created enormous interest as reinforcing element for use in various structures of polymer matrix composites. Majority of the commercial carbon fibers are produced from a PAN and pitch precursors. Since carbon fiber is the key constituent material in composite materials that contribute to the load carrying capability of composite structures any improvements in carbon fiber properties and manufacturing process is vital for the further improvement and application of composite structures. In this SBIR Phase I project we propose to develop pitch-based nanocomposite carbon fibers and use them for manufacturing of composite cylinders via a filament winding technique. These nanocomposite carbon fibers and the associated composite structures will possess excellent structural, thermal and electrical conductivity properties. Preliminary research results indicated that the proposed idea is very promising. The results of the proposed research will contribute to NASA's goal of performance enhancement, and reduction of launching and maintenance costs.