LIGHTWEIGHT THERMAL PROTECTION SYSTEM FOR HYPERSONIC VEHICLE CREW ESCAPE

A MAJOR BARRIER TO THE DEVELOPMENT OF EMERGENCY CREW ESCAPE SYSTEMS FOR HYPERSONIC SPACE-CAPABLE VEHICLES (I.E. NASP) IS THE EXCESSIVE WEIGHT ASSOCIATED WITH THE REQUIRED THERMAL PROTECTION HEAT SHIELD. IN THIS PHASE I PROGRAM, ULTRAMET PROPOSES TO UTILIZE ITS EXTENSIVE EXPERIENCE AND EXPERTISE IN THE FABRICATION OF LIGHTWEIGHT REFRACTORY FOAM STRUCTURES TO REDESIGN THE HEAT SHIELD USING NEW MATERIALS TO REDUCE THE WEIGHT BY AT LEAST 50%. A RETICULATED VITREOUS CARBON FOAM WILL BE INFILTRATED WITH HAFNIUM CARBIDE (HFC) BY CHEMICAL VAPOR INFILTRATION (CVI). THIS LIGHTWEIGHT REFRACTORY STRUCTURE WILL THEN BE TESTED FOR THERMAL INSULATION CAPACITY USING A FLAME IMPINGEMENT APPARATUS. FABRICATION AND STRUCTURAL ATTACHEMENT APPROACHES WILL ALSO BE INVESTIGATED AND EVALUATED. IN PHASE I, COUPONS OF REPRESENTATIVE MATERIALS WILL BE FABRICATED, TESTED, AND DELIVERED. IN PHASE II, A LARGER SUBSCALE PORTION OF THE HEAT SHIELD WILL BE CONSTRUCTED AND SUBJECTED TO MECHANICAL AND THERMAL TESTING IN SIMULATED TYPICAL OPERATING ENVIRONMENTS.