to begin closing as rapidly as possible the throat area will be fully closed as the chamber pressure reaches the fill pressure at the moment the pressure reaches the fill pressure opening of the fuel and oxidizer valves restarts the cycle the cycle time is may be as fast as 100 250 ms a control system algorithm may be used to maximize the time integrated impulse of the engine through manipulations of the fill time mixing time delay and rtvo and rtvc threshold levels existing software such as pincon u00ae developed by cfdrc may be use for example this software package allows for example the active control of pulse duration which is of importance in time critical maneuvers a non detonative pulsed bi propellant rocket was built to demonstrate an rtv nozzle combination a heavy wall demonstration motor was tested using a gaseous propellant combination of propane and nitrous oxide the motor generated brief chamber pressure pulses on the order of 500 700 psia using injector inlet pressures of only 40 50 psia this ratio will scale linearly to any desired value the motor therefore offers the efficiency of high pressure operation but does not require the heavy case weights and pressurant systems.