Abstract: A missile drive is provided comprising a single combustion chamber shared by a first, acceleration stage and a second, ramjet cruising stage, said chamber housing the solid propellant to be consumed during acceleration. At least one air inlet is opened at the end of the acceleration stage to allow an air flow to be introduced into the combustion chamber. Moreover, at least one additional exhaust outlet forming an additional nozzle is provided in the back of the combustion chamber and means are provided to seal off said additional exhaust outlet or outlets throughout the initial acceleration stage, such that said additional exhaust outlet or outlets contribute, together with the converging-diverging nozzle, to ejecting the exhaust gas during the ramjet cruising stage.

Abstract: The invention relates to a combustion chamber of a ramjet and booster rocket, which comprises an inner envelope provided with upstream lateral ports for the inlet of air and a downstream nozzle for ejecting the combustion gases, to allow functioning of the rocket at cruising speed; an outer envelope, concentric to the inner envelope and closed, with the exclusion of a single rear port for the ejection of the gases, to allow functioning of the rocket at launching speed; and separating means for separating from the combustion chamber at least a part of the outer envelope, at the end of the launching phase, in order to ensure the clearance of the upstream lateral ports of the inner envelope.