abstract:A rocket engine nozzle is a propelling nozzle (usually of the de Laval type) used in a rocket engine to expand and accelerate the combustion gases produced by burning propellants so that the exhaust gases exit the nozzle at hypersonic velocities.
On a hot June evening at a ramshackle former gliderport 30 miles east of Dallas, John Carmack's rocketengine lit up with its blue flame spewing from the nozzle.