Current space transportation systems such as expendable launch vehicles (ELVs) and the reusable Space Transportation System (space shuttle) are very expensive. In some instances they are based on 10 to 20 year old technologies. Newer, lower cost technologies must be applied to designing and manufacturing the next generation of vehicles. Competing effectively in the launch vehicle industry requires an order-of-magnitude reduction in the cost per pound of payloads delivered to orbit.Payload fairings are critical structural elements in all ELV systems. In addition to carrying and transmitting vehicle loads, they also protect payloads from severe launch and in-flight environments. Developing improved fairing hardware and the associated structural, thermal, acoustic, and separation subsystems is a major undertaking. It requires extensive design, analysis, testing, and systems integration activity.To maintain a competitive posture in the launch service industry, three years ago McDonnell Douglas Space System Company (MDSSC) initiated a research and development program on composite fairings. The program investigated and refined design and analysis, process techniques, and fabrication methods for large diameter composite fairings (1,2).*Substantial progress was achieved in composite fairing material selection, design and analysis, and manufacturing methods characterization. Eight composite fairing configurations with different constructions, and five aerodynamic forebody shapes with improved performance characteristics, were evaluated and studied. A final fairing configuration was selected for further study and the fabrication of a demonstration/test article is underway. This paper presents the composite fairing structural alternatives investigated and summarizes the results of the major trade studies undertaken.