retrorocket unit[航] 制动火箭发动机
retrorocket pack[航] 减速火箭发动机组
retrorocket engine制动火箭发动机
retrorocket landing用减速火箭着陆
retrorocket alignment减速火箭调准
stage-separation retrorocket级分离系统制动火箭
deorbit retrorocket engine脱离轨道用的制动火箭发动机
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)