Thermal Protection Systems Nondestructive Evaluation Tool

Based on the successful feasibility demonstration in Phase I, Physical Optics Corporation (POC) proposes to continue the development of a novel Thermal Protection System Nondestructive Evaluation Tool (THRON), which addresses NASA's need for evaluation of lightweight rigid and/or flexible ablative materials, and provides noncontact, one-sided in situ operation for accurate detection, identification, and precise spatial localization and measurements of internal and surface defects/voids, and evaluation of bondlines and in-depth integrity of such materials and also large-area multilayer thermal protection system (TPS) structures with complex geometries. THRON is based on POC-patented X-ray Compton imaging tomography and POC-patented apodized coded aperture X-ray imaging optics, substantially modified and optimized to meet NASA's requirements. The THRON Phase I prototype demonstrated excellent potential for detection and spatial localization of defects/voids with dimensions <6 mm by 6 mm by 6 mm, and bondline defects <12 mm by 12 mm by 200 &#956;m in TPS material and structures. At the end of Phase II, POC will perform a technology readiness level (TRL)-6 demonstration of THRON in POC's X-ray lab and/or at NASA facilities, and will deliver to NASA a working engineering model of an effective NDE tool.