The US Air Force is organizing combat units using unmanned aircraft. The Predator aircraft is being used. The new units will have 55 airmen, four Predators, ground station gear and a satellite dish (the Predator can be controlled via a satellite link). The Predator is being tested with Hellfire missiles. The Predators main mission will remain reconnaissance, but the addition of Hellfire missiles will enable Predators to hit targets on the move (and not likely to be found later when warplanes show up.) The Predator weight about a ton when ready for action and has a range of some 800 kilometers. Top speed is only about 140 kilometers an hour and max altitude is some 9,000 meters. The latest version is expected to cost some $27 million each. They don't require much maintenance, and can operate sixteen hours a day for six days a week over the length of a 90-180 day deployment.