In one example, a rocket nozzle assembly is disclosed that has stowed and deployed positions, and includes a casing including an outer wall and an inner surface, at least a portion of the inner surface defining a diverging region, wherein the casing defines a plurality of fin slots, and wherein each of the plurality of fin slots extend through the outer wall of the casing and the inner surface of the casing, and wherein the diverging region defines a bell-shaped contour. The assembly further includes a plurality of fins pivotally engaged to the casing, wherein in the stowed position, each of the plurality of fins extends into the diverging region through a respective one of the fin slots, and wherein in the deployed position, each of the plurality of fins extend outwardly from the casing.