Fathom is a 6” diameter aerodynamics test vehicle built to experience conditions that would be seen by a space shot vehicle. These conditions include reaching the same max speed, and max Q (maximum dynamic pressure). About 3.5 seconds into flight Fathom experienced a motorcase burn through. The avionics system was able to record data through out the flight and failure. The rocket landed a 10 minute walk away from the launch pad, and was still on fire when it was found. The burn through was found at a grain boundary.