The war in Afghanistan has made the Predator unmanned aerial vehicle or UAV a virtual household name. Its eye in the sky sensors have spotted buildups of al-Qaida and Taleban forces, allowing U.S. troops and manned planes to conduct precision counter-strikes.
Some Predators have even been equipped with Hellfire missiles, capable of carrying out their own attacks. But there are many other, even more sophisticated unmanned devices in development.
Its missions over Afghanistan have made the ungainly-looking propeller-powered Predator a star.
But it is far from the only unmanned device in the military's arsenals. There are others designed to fly in the air, some that can operate on land and still more for undersea or surface ocean activity. They have nicknames like Dragon Runner, Fire Scout and Spartan.
Some are quite large, like the Global Hawk UAV, another pilotless reconnaissance drone used in Afghanistan. With its wingspan of more than 35-meters, it is bigger than a Boeing 737 jetliner and far larger than the mere 15-meter wingspan Predator.
But consider the new, as-yet-unnamed micro UAV. Drawing on technological advances in miniaturization, it is just a little over 20 centimeters in diameter and weighs a mere two kilograms. It is designed to be carried by a single soldier, whose unit can use it on the battlefield to effectively peer around corners, over hills or into forests, enabling commanders to decide whether to strike, call for reinforcements or evade.
Colonel Steven Nichols of Army's Training and Doctrine Command is involved in the development of the micro UAV. Instead of using a winged-type configuration with a propeller like Predator, the micro UAV is a little flying hovercraft, one equipped with a video eye.
"It actually comes up to a hover and then it rotates over and goes into forward or rear or side flight and then it comes back to a hover wherever you want it to be," Mr. Nichols said.
Colonel Nichols said the devices would be a tremendous boon to field combat units. "We could take it down alleyways, let it look into a window. We could have it follow a vehicle. We could set it into a tree line so it could observe any kind of movement. We could also perch it on top of a building or a hill where it would sit there and monitor any movement at an intersection, roadway, walkway or those types of things," he said.
The micro UAV is still in the experimental phase.
But the Navy's UUV or undersea unmanned vehicle may be ready for actual deployment in the year 2005. This device resembles a torpedo - no surprise since it is designed to be launched from a submarine. It is also intended to carry out surveillance.
Captain David Olivier of the Navy's Submarine Warfare Division said unlike UAV designers, the UUV team faced special challenges.
"Because of the medium that we're working in, undersea, you don't have continuous communications because we really don't have a way of having long-range, underwater communications with the vehicle and so what we have to do is invest in what we call intelligent autonomy so the vehicle itself can make decisions and process information and then take it back to the host submarine. So we will not be, it's not like anybody on the submarine will have a joystick and be controlling this UUV," he said.
These intelligent torpedoes would be used like this: they would travel out from a submarine up to 160 kilometers and then search a box-shaped area of more than 100 square kilometers in size for hostile ships, mines or other obstacles. The torpedo would then return to the submarine to transmit its findings.
"There's a rendezvous location and then the submarine uses an acoustic beacon that the UUV will actually come in on like an airliner approaching a landing at an airport. The UUV will track in an acoustic beacon and it will basically be latched into a nose cone kind of assembly and then be guided back into the torpedo tube," Captain Olivier said.
Both men say the field of unmanned devices is an exciting one, especially since it holds the promise of saving human lives by letting machines do dull, dirty or dangerous missions into high-threat environments.
For the immediate future, these battlefield robots will probably remain tools, designed to assist human warfighters.
But in the long run, especially as more unmanned devices take on weapons capabilities, some military officers believe they could turn future combat into battles between machines, with human controllers sitting safely in distant bunkers.