X-ray fluorescence analysis for prediction of Space Shuttle solid rocket motor performance

Analysis of uncured solid propellant by X-ray fluorescence has been conducted on mixes prepared for four development motors produced for the Space Shuttle SRM Project. X-ray readings for chlorine (ammonium perchlorate) and iron (ferric oxide) were recorded for each mix during processing of the propellant. These values were used to predict burning rates for uncured acceptance, uncured acoustic emission and cured acoustic emission strands. Predicted burning rates all fell within control limits and when compared to actual burning rates, most were within experimental error. The X-ray analysis required one-third the time of current methods and met casting schedules.