Abstract: An initiator, for use in a gas generator, includes an enclosed volume in communication with apertures for introducing liquid propellant and pre-pressurization gas into a propellant ignition chamber, and an aperture for introducing combusted gasses into a gas generator. A mechanism for controlling when the gases are allowed to enter the gas generator, and a heater/electrode to initiate combustion of the liquid propellant, also communicate with the enclosed volume. The propellant and the pre-pressurization gas may be introduced together or through separate ports. The heater/electrode thermally decomposes and vaporizes the propellant causing pressurization of the ignition chamber until a critical value is reached and the propellant ignites and burns. The burning propellant increases the chamber pressure beyond a predetermined value thereby opening the controlling mechanism and allowing the combusted gases to be introduced into the gas generator combustion chamber.