There's a spare ammonia tank assembly, a spare flex hose rotary coupler, several remote power control modules and even a spare arm for the Special Purpose Dexterous Manipulator.

也有备用氨储罐群，1个备用的伸缩软管扭转耦合器，几个远程电源控制组件，甚或有1个用于专用灵巧机械手的备用手臂。