The primary NASA application of the proposed THRON is a compact NDE system that can be used for noncontact, one-sided in situ evaluation of structural integrity of TPS spacecraft material and structures, with the capabilities of accurate detection, identification, and spatial localization of internal and surface defects (cracks, voids, delaminations, porosity, and inclusions), and evaluation of bondlines and in-depth integrity of lightweight, rigid, and/or flexible ablative materials and large-area multilayer TPS structures with complex geometries. Additional NASA applications include in situ NDE/NDT of large-area nonuniform multilayer aluminum/titanium/composite structures with complicated geometry used in the development of advanced aircraft and spacecraft, providing accurate identification, localization, and measurements of all types of internal and surface defects. Military applications of THRON will include in situ NDE/NDT of large-area, nonuniform, multilayer, aluminum/titanium/composite structures with complex geometries, and also combined polymeric, ceramic, and metal matrix composite structures for U.S. Air Force, Navy, and Army aircraft. THRON-based systems (with minimum modifications of THRON) will also be used for NDE/NDT of airplane, helicopter, and missile parts containing electronics, mechanical components, propellants, explosives, etc., to detect defects and verify integrity. THRON-based systems can be incorporated by the U.S. Air Force, Navy, and Army as a reliable, rapid, robotic, easy-to-use NDE/NDT system. Potential DHS applications include the detection of vehicle-borne contraband, drugs, and explosives. The commercial applicability of THRON includes its use for in situ NDE/NDT of large-area nonuniform multilayer aluminum/titanium/composite structures with complex geometries in aging and modern commercial aircraft, spacecraft, light marine vessels, and any application requiring defect detection for multilayer ceramic, composite, metallic, and plastic nonuniform structures.