Real-Time Health Monitoring for Solid Rocket Motors

ABSTRACT: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 Concepts 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.