Opportunities for retrofit and new application in turbine engine systems also exist. The potential low cost and high temperature capability could lend itself to these applications for internal hot gas path parts. Similar requirements for high-temperature materials exist for commercial/industrial applications as well. Although less aggressive than the aerospace/defense and nuclear energy-related initiatives, programs are in place for evaluating reinforced ceramics for land-based turbine components, catathermal combustion devices, heat exchangers and radiant burners, which represent opportunities in energy and pollution abatement technologies that may mature over the next 10 or so years. The development of advanced ceramic composite materials and components with enhanced thermal-structural performance over those currently available could directly support future enabling technologies for hypersonic propulsion and hot structures. Applications for ceramic composites in advanced airbreathing combined-cycle propulsion systems and control surfaces for reusable hypervelocity and exo/transatmospheric aerospace vehicles are directly addressed by this technology. These potential applications are critically dependent on the development of lower cost advanced materials capable of high-performance load-bearing operation up to and beyond 1500o
F). Successful demonstration of the life at temperature of the CMC concept could result in a valuable near term increase in airframe performance and reliability for a variety of hot structures and thermal protection systems critical to both DoD and NASA highspeed aircraft and re-entry vehicles.