YUMA PROVING GROUND, Ariz.-- What do you call a new lightweight vehicle capable of monitoring its own vital signs, lowering itself to within inches of the ground, and providing Soldiers with a high level of scalable protection and improved sustainment?

For the Army, the vehicle is the sleek, agile and fortress-strong replacement for at least some of the High Mobility Multipurpose Wheeled Vehicle (HMMWV) fleet -- the Joint Light Tactical Vehicle (JLTV).

The JLTV's position is not an easy one, for the Humvee is one of the most iconic wheeled vehicles in military history. Since its introduction in 1984 as the replacement for the equally influential jeep, the versatile HMMWV has seen action in every theater of operations the U.S. military has since served in. More than 150,000 of the venerable vehicles have been used by American Soldiers.

Though rugged and remarkably fast for a military vehicle, the HMMWV's lack of armor proved fatal to many Soldiers when confronted with the horrific destructive power of improvised explosive devices (IEDs) in the early years of combat in Iraq. Added armor helped blunt the impact of the explosions, but the extra weight impacted the vehicles' balance and stability. Additionally, when the HMMWVs were outfitted with sophisticated electronic counter-IED devices, many of which were tested at YPG, the electricity necessary to power the items overwhelmed the vehicle's dated electrical system. To bridge the capability gap, JLTV has been designed to provide increased electrical power, both moving and stationary.

The JLTV incorporates a long list of upgrades that will make it significantly more advanced than the current tactical vehicle fleet. It sports run-flat tires, jam-resistant doors, and an automatic fire extinguishing system in the event the vehicle is subject to an IED. Like the HMMWV, the JLTV will be available to serve a variety of combat missions in several configurations, from infantry carriers to armed escort vehicles to ambulances. All of its variants have a detachable trailer capable of pulling the same payload as the vehicle it is attached to. Another useful feature is the high-profile vehicle's ability to be lowered to within inches of the ground to facilitate boarding and stowage on ships.

During the initial technology development phase of testing that began in 2009, three vendors each provided three vehicles to be put through rigorous testing across YPG's punishing road courses, as well as on the test track operated jointly by the Army and General Motors. The final selection was made last August, and YPG is currently conducting production performance testing as the vehicles roll off the assembly line.

"We're doing reliability and maintainability testing, and a whole slew of performance testing," said Issac Rodriguez, team leader.

In addition to running the vehicles across 16,000 miles of paved, secondary, and cross country roads, YPG testers are testing everything from the overhead gunner's protection kit to vehicle's active suspension system. For example, if the vehicle is parked on a 20% side slope, can it be levelled out to allow occupants to open and exit from the vehicle's heavy armored doors safely and effectively?

"We're doing simulated missions," said Rodriguez. "We're checking out all of the onboard systems: we're cycling doors and windshield wipers, and everything else that has a purpose."

The services are in the process of developing and refining their respective tactical wheeled vehicles strategies, therefore a final planned quantity has not yet been determined. Currently, the Army is intends to purchase 55,000 of the vehicle within the next 15 to 20 years, with the Marine Corps adding an additional 5,500. YPG testing is done with the dual branch use in mind.

"This is a joint program between the Army and Marine Corps, so it has to accommodate both services' onboard systems, radios, and other equipment," said Rodriguez.

Operational testing of the vehicle is scheduled for next year, and Rodriguez praises the efforts of all YPG personnel involved in the test, from vehicle and weapons operators to metrology and simulation workers.

"It's all hands on deck," he said. "The entire team is making a valiant effort to meet the program's aggressive schedule. If they weren't getting the data in hand in time, the operational test's start would be impacted."