Probabilistic risk assessment (PRA) approach for the next generation launch technology (NGLT) program turbine-based combined cycle (TBCC) architecture 6 launch vehicle

The NASA Next Generation Launch Technology (NGLT) Program is evaluating various concepts for less expensive and reduced-risk access to space. Critical to these goals are more reliable and easily maintained vehicles, with high fidelity integrated vehicle health management (IVHM) systems, rapid turn-around time and dual-use technology. The initial application of probabilistic risk assessment (PRA) on the turbine-based combined cycle (TBCC) architecture 6 concept has helped to define key assumptions necessary to make the development of the architecture 6 concept successful. While the final figures of merit (FOMs) will be based on successfully developing and testing the vehicle, preliminary FOMs can be used now for basic trades between propulsion and staging concepts, thus providing a valuable tool to evaluate the overall trade space between highly divergent concepts. Reliability analysis, probabilistic design methods (PDM), and probabilistic risk assessment can be integrated to evaluate overall systems architecture, a complete mission model, and a fleet logistics model. In addition, the PRA may be used to evaluate and compare a high and low energy crew escape system.