Holographic subsurface radar for diagnostics of cryogenic fuel tank thermal insulation of space vehicles

Analysis of critical conditions on the reusable spacecrafts Columbia (USA), and Buran (Russia) related to defects in insulation and heat-protection coatings have been performed. It is shown that the existing methods of non-destructive testing, including ultrasonics, failed to prevent the disaster of the Space Shuttle Columbia and serious incidents involving the spacecraft Buran during its only flight. A new method for using the holographic subsurface radar RASCAN-5/15000 which reveals the internal defects of the coating was proposed, and experiments on models of thermal insulation coatings were performed. The experimental results were displayed in the form of radar images on which defects in the heat insulation provided a good contrast. The article reflects preliminary study and further efforts are needed to improve resolution of the technology.