Demonstration of remote fiber optic spectroscopy using mid-IR sensors for in-situ monitoring of solid rocket propellent cure and aging

Abstract

A study of real-time in situ monitoring of the chemical states of urethane cross-linked solid rocket propellant during cure and aging using an embedded fiber optic sensor and a Fourier transform IR spectrometer is presented. The aging study focused on the monitoring and identification of chemical species that migrate across the propellant-insulation bondline. In this work, a short length of tapered chalcogenide fiber was used as the sensor. The segment of fiber containing the taper sensor was mounted in a temperature controlled aluminum boat to which either inert or live propellant samples were added. The spectral data collected over a six month period indicated that the equipment and sensors were suitable for monitoring the degree of curve and contaminant migration in solid rocket propellant.