09 May 12. The unattended steering wheel on the 15-ton military truck jerked sharply back and forth as the vehicle’s huge tires bounced down a rain-scarred ravine through mounds of mine rubble on a rugged hillside near Pittsburgh.

An Oshkosh truck using the TerraMax autonomous driving system drives along a test course

Oshkosh Corp engineer Noah Zych, perched in the driver’s seat, kept his hands in his lap and away from the gyrating wheel as the vehicle reached the bottom of the slope and slammed into a puddle, coating the windshield in a blinding sheet of mud.

As the truck growled up another rise and started back down again, Zych reached up and flicked a wiper switch to brush away the slurry, then put his hands back in his lap.

“We haven’t automated those yet,” he explained, referring to the windshield wipers, as the robotic truck reached the bottom of the hill and executed a perfect hairpin turn.

Ten years of war in Afghanistan and Iraq have put a spotlight on the growing use of unmanned systems in the skies over the battlefield, from the high-flying Global Hawk to the lethal Predator aircraft and the hand-launched Raven.

But on the ground, thousands of small, remotely operated robots also have proven their value in dealing with roadside bombs, a lethal threat to U.S. troops in both wars. Of more than 6,000 robots deployed, about 750 have been destroyed in action, saving at least that many human lives, the Pentagon’s Robotics Systems Joint Program Office estimates.

Only now is robotics research nearing the stage that the military may soon be able to deploy large ground vehicles capable of performing tasks on their own with little human involvement. The results, among other things, could be more saved lives, less wear and tear on the troops, and reduced fuel consumption.

Full autonomy, engineers say, is still years away.

“The ground domain is much, much tougher than the air domain because it’s so dynamic,” said Myron Mills, who has worked on both aerial and ground robotic systems and now manages an autonomous vehicle program for Maryland-headquartered Lockheed Martin Corp.

Mills said autonomous ground systems face a series of challenges such as dust, fog and debris – as well as avoiding civilians and troops. A path may be passable one moment and littered with obstacles a half hour later due to battle damage.

“It’s just a very, very tough and chaotic environment,” Mills said. “The hardest thing to deal with has been figuring out how to make the system usable for the soldiers and be able to cope with the chaotic environment.”

Enough progress has been made that Lockheed’s Squad Mission Support System, a 5,000-pound (2,268 kg) vehicle designed to carry backpacks and other gear for overloaded foot soldiers, is now being tested in Afghanistan.

Wisconsin-based Oshkosh’s unmanned vehicle system, which would allow one person to control several heavy cargo trucks, has been assessed by U.S. Marine Corps drivers in the United States and is in the final stages of concept development.

A four-legged walking robot designed to carry loads for combat foot patrols – the Legged Squad Support System, or LS3 – is due to undergo testing and assessment with troops toward the end of the year, developers at Massachusetts-based Boston Dynamics said.

The potential payoffs could be huge. Robotic systems could “radically alter the balance” among the variables that are driving the high cost of combat vehicles, according to a report for the Pentagon last year by the nonprofit Rand Corporation.

Taking drivers out of the trucks would reduce the need for thick armor plating that increases weight, boosts the need for ever more powerful engines and ratchets up fuel consumption in places like Afghanistan, where the cost of delivering petroleum can run as high as $400 per gallon, the Rand report said.

Advances are significant enough that military officials say they are committed to continued develo