Payload Separation and Thrust Termination in A Solid-Propellant Rocket Motor

A command method for thrust reduction and/or thrust termination of a solid-propellant rocket motor-called project Shavetail-was demonstrated successfully in flight by Jet Propulsion Laboratory.

Thrust reduction is achieved by the separation of a portion of the nozzle to increase the throat area. The chamber pressure is lowered and motor continues to burn at a vernier level of thrust. At any time before motor burnout, upon command from guidance, thrust cancellation and motor separation from the payload are achieved by opening an orifice in the head end of the motor.