NASA and DoD are seeking economical and high-performance bipropellant thrusters for various applications. These goals cannot be achieved using the silicided C103 chambers in current use. Ultramet has developed and successfully demonstrated carbon fiber-reinforced zirconium carbide (C/ZrC) and carbon fiber-reinforced zirconium-silicon carbide (C/Zr-Si-C) ceramic matrix composites (CMCs) for use in liquid propellant applications up to 4200o
F. Although the density of these CMCs is less than that of C103, further reducing overall weight is desired with a target goal of 2.6 g/cm3. Carbon/carbon (C/C) is widely used because of its light weight and high specific strength at elevated temperatures. However, adequate long-term protection of C/C is the limiting factor for its use in liquid propellant propulsion components. Ultramet will combine the light weight of C/C and the ultrahigh temperature oxidation resistance of C/Zr-Si-C CMCs in a unique laminate composite. This system will possess an overall density that is similar to C/SiC while increasing the operating temperature to 4000o
F in liquid propulsion applications. Net-shape fabrication of CMC-lined C/C combustion chambers will be accomplished by adapting an innovative variant of Ultramet's melt infiltration technology.