SBIR-STTR Award

A Health Monitoring Sensor for Solid Rocket Motors (SRMs) uses actual polymeric components of propellant in a tiny new sensor called AgeAlert™. These sensors will provide real-time data corresponding to aging of the propellant. The sensors are mounted external to the propellant and automatically track degradation passively without electrical power until interrogated. They are extremely accurate because they degrade in the same way under the same environment as the propellant in motor itself. AgeAlert sensors are attached to a rocket motor so they “see” the same environment as the propellant being monitored. Applications include (1) data for verifying existing and proposed SRM health management models based on environmental sensors and (2) stand-alone “Smart Shelf-Life™” labels attached to small ordnance items or packaging to monitor aging of the propellant during transportation, storage and deployment. These smart labels provide immediate “go, no-go” indication to the user in the field without special training or equipment. This project expands on successful research by Polymer Aging Concepts, Inc. for prototype sensors to monitoring aging of electrical insulation materials in nuclear power plant components. Participation by a SRM prime contractor in the selection propellant materials and sensor data correlation optimize probabilities of success and technology implementation.

Benefit:
These innovative sensors will greatly advance Integrated Vehicle Health Management (IVHM) of solid rocket motors and potentially save up to 50% of the cost of present methods utilizing destructive testing while improving reliability and safety of military and commercial solid rocket motor assets. The accuracy and in-situ features of AgeAlert technology means that not only will operators in the field benefit with a smart label which provides continuous status as to the reliability and safety of solid rocket motor ordnance, but objective data is readily available on individual assets to support mechanistic modeling for surveillance and shelf life extension programs. It will reduce the need for embedded sensors which add complexity and uncertainty due to stress risers in operational assets. This new heath monitoring approach is very cost effective since (1) the sensor utilizes inexpensive fillers used in the composite sensors, (2) sensor smart labels and readers are simple and reliable because they are based on the inherent “variable resistor” output of the sensors, and (3) field interpretation of “Smart Shelf-Life” labels utilizing AgeAlert sensors is simple pass/fail requiring no special operator training or equipment. Since no electrical power is required to respond to the degradation, the sensors can be incorporated into passive (no battery) radio frequency identification (RFID) devices allowing a single smart label to uniquely identify the item and identify significantly degraded items before reliability or safety are impaired. Potential commercial applications include sensors and smart labels for military and commercial solid rocket motor assets. The approach of this proposal could be expanded to monitor aging of other propellants used in ammunition, fuses, explosives and pyrotechnic devices. Since AgeAlert technology is potentially applicable to any product comprising polymeric components, future health monitoring applications include advanced composite structural materials, seals, gaskets, tires, protective coatings and electronic packaging. Strong intellectual property and process “know-how” in fabricating AgeAlert sensors provides significant opportunity for high technology domestic manufacturing jobs.

Keywords:
Solid Rocket Motors, Propellant Aging, Propellant Degradation, Degradation Sensors, Shelf Life Extension, Aging Models, Smart Labels, Integrated Vehicle Health Monitoring

A Propellant Health Monitoring (PHM) Sensor for Solid Rocket Motors (SRMs) utilizes actual propellant components in a tiny new sensor called AgeAlert?. These sensors provide real-time data corresponding to mechanical property degradation resulting from environmental aging of propellants. The sensors are mounted external to the propellant and automatically track degradation passively without embedment. They are accurate because the sensing element degrades in the same way under the same environment as the propellant in motor itself. Applications include (1) mechanical property data for verifying existing strategic SRM propellant models and (2) stand-alone ?Smart Shelf-Life?? labels attached to tactical SRMs or packaging to monitor aging and provide remaining life of the propellant throughout life of the asset. These smart labels provide immediate ?go, no-go? indication to the user in the field without special training or equipment. This Phase II project will fabricate and bench test PHM sensors and health monitoring hardware/software for a live propellant used in strategic and tactical SRMs. Polymer Aging Concept?s experience in fabricating PHM sensors from propellant binders demonstrated feasibility of the approach. Participation by a SRM prime contractor in the propellant selection, health monitoring hardware/software design and bench top demonstrations optimizes probabilities of success and technology implementation.

Benefit:
This Phase II project will mature the Technical Readiness Level (TRL) of PHM sensors from TRL 3 (active R&D is initiated) to TRL 5 (component and/or breadboard validation in relevant environment). Commercialization of PHM sensors will greatly advance Integrated Vehicle Health Management (IVHM) of strategic Solid Rocket Motors (SRMs) by providing real time, non-destructive propellant properties for aging model verification. Internal Air Force studies have shown potential savings of up to 50% of the lifecycle costs of strategic assets by SRM heath monitoring improvements that reduce destructive testing and premature removal of assets from service. PHM sensors, integrated into passive Radio Frequency Identification (RFID) tags attached to tactical SRMs will provide passive (no battery) ?Smart Shelf Life? tags which allow instant reading in the field of SRM propellant status (?go, no-go? or percent remaining lifetime) without special training or specialized equipment. These Smart Shelf Life tags will improve ordnance reliability by identifying assets which degrade prematurely from extreme environments, while reducing lifecycle costs by reducing destructive testing requirements and premature removal from service. The unique ?self-integrating? feature of AgeAlert PHM sensors means that hardware and software is greatly simplified compared to environmental sensors and modeling approaches. Smart Shelf Life tags for tactical assets are estimated to cost approximately $50/tag in full production quantities. Commercialization potential and market interest has been demonstrated by strong documented interest by Joint forces (US Army, ARDEC), and several SRM prime contractors. Since AgeAlert technology is potentially applicable to any product comprising polymeric components, future health monitoring applications include sensors and Smart Shelf Life tags for gun propellants, advanced composite structural materials, seals, gaskets, tires, protective coatings and electronic packaging. Strong intellectual property and process ?know-how? in fabricating AgeAlert sensors and demonstrated manufacturability provides significant opportunity for high technology domestic manufacturing jobs.

Keywords:
Solid Rocket Motors, Propellant Aging, Propellant Health Monitoring, Degradation Sensors, Shelf Life Extension, Aging Models, Smart Labels, Integrated Vehicle Health Monitorin