A need exists for a reliable, non-destructive, in-situ method to monitor the chemistry of solid rocket motor propellant to determine its health and stability during the service life of the motor. Ideally, the sensor would be able to monitor the chemical components of the motor and not affect the propellant, the liner, or the rocket motor composite casing. The proposed program will develop an optical fiber-based Raman scattering instrument to monitor curing, migration of contaminates, and other aging effects that could alter the propellant chemistry. Raman spectroscopic analysis can be made via small, inert, optical fiber microprobes (0.1 inch OD). In Phase I, we will collect Raman spectra from multiple Air Force rocket motor formulations using Raman microprobes that have been cast into propellants. The Raman spectra will be used to monitor curing, migration of potential contaminants, and other aging effects that can alter propellant chemistry. In phase II we will develop smaller and more robust microprobes that would be suitable for direct implantation into real rocket motors for monitoring long-term, real-time chemical composition of rocket motor propellant during accelerated aging/curing studies. This work could greatly reduce the current expense of ongoing non-destructive testing by major rocket motor contractors.
Benefits: Rapid, in-situ determination of solid rocket propellant chemistry could greatly reduce the need for expensive destructive testing to determine the health of new and aging rocket motors. In-situ detection can be used to monitor aging effects that alter the propellants chemistry, and also determine the service life of the motor. Similar technology can be applied to many composite manufacturing systems such as aircraft and vehicle manufacturing where chemical stability issues are very important for service life.)
Keywords: Fiber-Coupled Raman, In-Situ Rocket Motor Health Monitoring
