Abstract: T－ray imaging technology is applied to identify defects in space shuttle foam insulation. The temporal waveform of the terahertz pulse of each pixel is obtained by scanning every layer of the foam sample. Multiple imaging analysis techniques are implemented to analyze waveform changes, in order to pin－point the size, shape, location and type of defects in each layer. T－ray imaging has become a novel non－destructive detection technology and will be applied by NASA in safety tests for future launches.