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Terahertz Computed Tomography of NASA Thermal Protection System MaterialsA terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.
Document ID
Document Type
Conference Paper
Roth, D. J.
(NASA Glenn Research Center Cleveland, OH, United States)
Reyes-Rodriguez, S.
(Michigan State Univ. East Lansing, MI, United States)
Zimdars, D. A.
(Picometrix, Inc. Ann Arbor, MI, United States)
Rauser, R. W.
(Toledo Univ. Toledo, OH, United States)
Ussery, W. W.
(Lockheed Martin Space Systems Co. Denver, CO, United States)
Date Acquired
August 25, 2013
Publication Date
March 1, 2011
Subject Category
Quality Assurance And Reliability
Report/Patent Number
Meeting Information
38th Annual Review of Progress in Quantitative Nondestructive Evaluation(Burlington, VT)
Distribution Limits
Public Use Permitted.
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