Reflection from Sprayed-on-Foam Air Gap
After the Space Shuttle Columbia disaster in 2003, NASA began examining the exterior of the shuttle external fuel tank using the Picometrix T-Ray® QA1000.
Terahertz data was utilized to construct an image like that the right. Flaws and delaminations in the sprayed on foam insulation are readily visible.
The power of being able to scan the sensor heads at the end of a fiber umbilical becomes obvious when examining something as big as the external fuel tank.