After working with the steel-cased solid-rocket motors for the Titan III, 34D, and IVA vehicles for 25 years, Aerospace assisted the development and qualification of the graphite-epoxy composite solid-rocket motor upgrade. The primary advantages of the composite-cased motors included higher performance, lighter spent weight, and greater nozzle control. Higher reliability was also achieved through the use of fewer components; the composite version has only two segment joints per motor, as opposed to the eight joints for the segments and closures on the steel model.
Aerospace contributed substantially to the design of the composite-to-metal joint as well as to the propellant-grain design for the forward, center, and aft segments. Aerospace personnel participated extensively in all seven qualification motor firings. Working alongside the contractor and manufacturer, Aerospace provided expertise in the development of a comprehensive nondestructive evaluation program for the upgraded motor components. When production or qualification problems were encountered, Aerospace joined with the contractors to resolve the issues and continue processing. All the upgraded propulsion, structural, hydraulic, electrical, and avionics components were checked by Aerospace as part of the hardware acceptance review process. Equally important was the participation of Aerospace during the assembly and testing of the Titan IVB vehicle hardware at the launch bases.
With 12 of the 17 Titan IVB launches complete, the upgraded motors have flown successfully with predictable and consistent performance.
—Fred Buechler