Each craft had to hit the atmosphere right , deploy its parachute , turn on retrorockets and inflate airbags just before touchdown 每架探测器必须以正确的角度进入大气,展开降落伞,点燃制动火箭,并在着陆瞬间为安全气囊充气。
英文解释
a small rocket engine on a larger rocket or spacecraft that is fired to slow or alter its course
百科解释
A retrorocket (short for retrograde rocket) is a rocket engine providing thrust opposing the motion of a vehicle, thereby causing it to decelerate. They have mostly been used in spacecraft.