Session
Technical Session VIII: Launch Vehicles
Abstract
The methods used by Thiokol Corporation to achieve unprecedented performance tailorability in the Castor 120™ solid rocket motor will be discussed.. This motor is a 120,000-pound class motor designed for use on expendable launch vehicle systems. It employs a carbon-epoxy composite case, Class 1.3 HTPB propellant, and a vectorable nozzle. A key objective was to build a motor that could be used in fast stage, strap-on, and second stage applications. Each application has differing thrust, action time, nozzle vector duty cycle. and structural capability requirements. In contrast, most existing large solid rocket motors are designed for a single application. With no provisions for meeting the needs of alternate launch vehicles. This results in high recurring and non-recurring costs and long development cycles. To meet all of these needs without the cost and schedule impacts associated with major redesigns. Thiokol Corporation has incorporated several key design features in this one motor. The propellant is cast using a slightly tapered casting core without fms. The grain features required to achieve the desired ballistic performance are machined into the cured propellant this innovative. high-volume propellant machining tool was developed recently by Thiokol and a patent application is pending. High factors of safety were built into all of the critical components allowing us to change functional characteristics by a wider margin than usual without jeopardizing flight reliability. These concepts are a major step forward for the solid rocket motor industry providing a truly tailorable motor that can be used in a wide variety of applications without major cost impacts on the launch vehicle supplier or the end user.
Achieving Performance Taliorability in the Castor 120 Solid Rocket Motor
The methods used by Thiokol Corporation to achieve unprecedented performance tailorability in the Castor 120™ solid rocket motor will be discussed.. This motor is a 120,000-pound class motor designed for use on expendable launch vehicle systems. It employs a carbon-epoxy composite case, Class 1.3 HTPB propellant, and a vectorable nozzle. A key objective was to build a motor that could be used in fast stage, strap-on, and second stage applications. Each application has differing thrust, action time, nozzle vector duty cycle. and structural capability requirements. In contrast, most existing large solid rocket motors are designed for a single application. With no provisions for meeting the needs of alternate launch vehicles. This results in high recurring and non-recurring costs and long development cycles. To meet all of these needs without the cost and schedule impacts associated with major redesigns. Thiokol Corporation has incorporated several key design features in this one motor. The propellant is cast using a slightly tapered casting core without fms. The grain features required to achieve the desired ballistic performance are machined into the cured propellant this innovative. high-volume propellant machining tool was developed recently by Thiokol and a patent application is pending. High factors of safety were built into all of the critical components allowing us to change functional characteristics by a wider margin than usual without jeopardizing flight reliability. These concepts are a major step forward for the solid rocket motor industry providing a truly tailorable motor that can be used in a wide variety of applications without major cost impacts on the launch vehicle supplier or the end user.
