retro-rocket motor制动火箭发动机
solid-state retro-rocket unit固体燃料火箭推进器
de-orbit-retro rocket脱离轨道制动火箭发动机
N（名词） a small auxiliary rocket engine on a larger rocket, missile, or spacecraft, that produces thrust in the opposite direction to the direction of flight in order to decelerate the vehicle or make it move backwards 大型火箭、导弹或航天器上的备用发动机; 产生和航线反方向的猛推，以使其减速或向后退 (Often shortened to retro)