Melody Rea
Missouri University of Science & Technology
Marshall Space Flight Center
Supervisor: Frank Hepburn

Abstract
Non-Destructive Evaluation (NDE) is a branch of research and engineering dedicated to detecting various types of flaws in many different kinds of materials without changing the sample. NDE can be either contact or non-contact. Various types of NDE include, but are not limited to, dye penetrant, magnetic particle, ultrasonics, X-Ray, and microwave. Reza Zoughi describes the need for microwave/millimeter wave (MMW) NDE in his book, Microwave None-Destructive Testing and Evaluation. “With the ever expanding materials technology, by which lighter, stiffer, stronger and more durable electrically insulating composites/materials [dielectrics] are replacing metals in many applications, there are demands for alternative inspection techniques to the existing Nondestructive Evaluation (NDE) methods. Microwave/Millimeter Wave NDE is a method that will provide an array of information from these newer materials including images” (Zoughi). As Zoughi alludes to, most current methods of NDE fail when evaluating dielectric materials, such as composites, ceramics, plastics, and foam etc. and such failures could result in lost time, equipment damage, injury or even loss of life. MMW NDE is proving to be very effective at detecting small air pockets, delaminations, and disbonds in dielectrics and composites and surface cracks and flaws in metals covered by dielectric materials such as paint, rubber or rust. Despite still being in its infancy, millimeter microwave NDE is quickly proving its versatility by providing clear 2-D and 3-D images without many of the problems generated by other NDE methods.
NOTE: This work was sponsored by the Exploration Systems Mission Directorate (ESMD) Space Grant Internship Program.