Abstract: Accurate modeling of flaw behavior in both propellant-liner-insulation and insulation-to-insulation interfaces is required for flight certification of NASA’s Space Launch System solid rocket booster. In-situ monitoring of the flaw propagation using nondestructive test methods such as X-ray and ultrasonic testing allows pressure and volumetric flow data to be correlated with the time of flaw propagation during pressurization. The use of X-ray and ultrasonic test inspection allowed physical fla…