Non-Destructive Evaluation (NDE) of Missile Launcher Ablatives

MK-41 VLS exhaust paths are lined with ablative insulation that chars and ablates with each missile firing. There is no way to inspect, in-situ, chemical and physical changes to the ablatives. Such measurements are complicated because ablative materials: vary with location, are low density, and degrade non-linearly with firings.Failure of VLS insulation is not an option – but the usage life of these large, complex, expensive structures must be maximized.The research team proposes to develop and field a fast, easy to use, nondestructive method to assess the condition of missile launcher ablatives and to determine the remaining number of firings that can be safely performed. The technology will be based on low power, non-ionizing microwave energy reflection measurements. Microwave NDT has been used for over two decades to inspect throughout the entire thickness of low density, non-conductive materials to detect flaws; measure thickness; and assess chemical and physical changes. For layered structures, it can discern which layers contain which variations and/or defects.Phase I will show that we can simultaneously evaluate chemical/physical degradation to MK41 ablatives and measure ablative thickness. The thickness and materials properties measured via NDT will be correlated to ground truth materials condition and thickness.