Non-Destructive Propellant Sensor

Many rocket motors used by the Navy are powered using solid rocket propellants (SRP). Over time and with exposure to varying environmental conditions, the elastomeric binder material undergoes oxidative degradation leading to embrittlement of the SRP.  Current methods of non-destructive testing (NDT) using ultrasound exist to inspect SRPs for major defects that occur when aged SRPs exhibiting such brittleness experience failures such as, large cracks, fissures, and delamination in normal transportation, storage, and operating situations. However, these methods do not provide a mode of inspection to reliably detect changes in the mechanical integrity of the propellent prior to the point of failure. METSS is proposing an optimized method of ultrasonic NDT to detect and correlate aging with mechanical degradation of SRP materials. Monitoring changes in ultrasonic wave velocity is a well-supported method of detecting aging in SRP. METSS seeks to fill the technology gap by connecting ultrasonic measurements to mechanical degradation and integrating it with a compact, field deployable system focusing on ease of use for a single operator. This will allow for fast, efficient, and accurate field testing of the SRP motors to monitor propellent properties that could lead to mechanical failure or alter the response of the propellant.