One reason the Predator UAV was so successful was its targeting system. The MTS (Multispectral Targeting System) is pod mounted under the nose of the Predator. Moving in all directions on a gimbaled mount, the MTS has a 680x480 pixel infrared camera (it senses heat and can thus see in the dark) and a color television. Also in the pod is a laser for marking targets for laser guided bombs, a GPS and inertial guidance system. The MTS can guide weapons (like Hellfire) missiles fired by the Predator, or paint a target with laser light for laser guided bombs or missiles dropped from other aircraft. When the MTS was field tested in 2001, it was so successful, and the Air Force and CIA were so eager to get more of them, that the lengthy engineering and manufacturing development phase of the procurement phase was skipped so that the manufacturer could immediately start production. Thus Predator had truly become a Predator by September 11, 2001 and that's why the UAV was firing Hellfire missiles at targets before the end of 2001.