Anti-parallel alignment is therefore not quite as serious as saturation but must still be avoided. It is theoretically possible with any number of CMGs; as long as some rotors are aligned parallel along a particular axis, and all the others point in exactly the opposite direction, there is no saturation but still no roll control about that axis. With three or more CMGs the situation can be immediately rectified simply by redistributing the existing total angular momentum among the rotors (even if that total is zero). In practice the CMG control program will continuously redistribute the total angular momentum to avoid the situation arising in the first place.