A robot, equipped with an M240 machine gun, moves through the darkness until it stops under a stand of trees 100 yards from its squad of U.S. troops. The robot uses thermal imaging to detect enemy combatants hiding up ahead and aims its gun at them.

With a single command from its human controller, who is with the squad 100 yards back, the robot opens fire and takes out the enemy, saving the troops from a potentially deadly attack.

A weaponized robot acting as a member of a squad of U.S. soldiers fighting on the battlefield is no longer science fiction. They may not be two-legged, humanoid robots yet, but with wheels or tracks they are able to follow troops through a wide range of terrain and back them up in battle.

Both the U.S. Army and the U.S. Marines have tested prototypes of weaponized robots on the battlefield. However, armed robots are not currently in the Army's inventory of weapons.

Army leaders got a look at what technology is available for the battlefield during a robotic live-fire demonstration at Fort Benning, Ga., this week.

Commercial companies showed off their weaponized robots to U.S. Army officers at Fort Benning, Ga., this week. Military leaders were looking to see what the technology is capable of and how it could be used on the battlefield. (Video: Keith Shaw/IDG Enterprise)

"We were hoping to see how they remotely control lethal weapons," said Lt. Col. Willie Smith, chief of Unmanned Ground Vehicles at Fort Benning. "We were pleased with what we saw here. The technology is getting to be where it needs to be. It's a start."

Smith, who was looking to see multiple weapons systems mounted on the robots, said he's uncertain how soon the Army will begin using weaponized robots on the battlefield, but he's hoping it will happen within five years.

"They're not just tools, but members of the squad. That's the goal," Smith said. "A robot becoming a member of the squad, we see that as a matter of training ... I think there's more work to be done, but I'm expecting we'll get there."

Four robotics companies -- Northrop Grumman, HDT Robotics, iRobot Corp. and QinetiQ -- demonstrated their robots' abilities to fire machine guns and take out pop-up targets from a distance of 150 meters during the live-fire demonstration Thursday.

Phil Coker, director of integrated platform systems at Northrop Grumman, said its robot, the CaMEL (for Carry-all Mechanized Equipment Landrover), can run for 24 hours on three-and-a-half gallons of fuel, and can be equipped with a grenade launcher, an automatic weapon and anti-tank missiles.

The CaMEL also can identify targets from three-and-a-half kilometers away, using a daylight telescope or thermal imaging. The robot also can be dropped into a war zone from a helicopter or a plane.

The robots can be controlled, tetherless, from a handheld device that looks much like a gaming control, a laptop computer or a tablet attached to a vest that a soldier wears.

The vest, which weighs about 10 pounds, carries a battery, the handheld controller and a tablet that flips down from the soldier's chest so he can see what the robot sees. That means the soldier doesn't have to see the live target himself.

The robots also can be operated, via satellite radio communications, from hundreds of miles away.