Exoskeletons, ‘Smart’ Parachutes Could Reduce Soldiers’ Loads
An especially large figure is dressed in the improved outer-tactical vest currently being used by troops in Afghanistan. Natick officials had to have the dummy custom made because they couldn’t find a commercially available mannequin that could support the armor.
Soldiers are used to carrying the equivalent of another human being with them wherever they go. The vest can account for about 35 pounds of that load, but body armor is only the beginning. Troops must also carry weapons, ammunition, radios and batteries, among other items. They often end up lugging around 120 pounds of gear, not exactly an ideal task while under constant threat in the mountains of Afghanistan.
Scientists at the Natick Soldier Research, Development and Engineering Center battle with the problem of soldier load every day. They are working with industry to reduce the weight that troops carry, studying concepts that take into account everything from logistics to body armor to the changing sizes of service members.
Nearly everything that scientists can come up with will be affected by the results of an Army-wide anthropometric survey during which Natick is using 3D body, head and foot scanners to measure the sizes and shapes of soldiers across the force. The 18-month program will wrap up early next year and will have an impact on everything from uniforms and equipment to aircraft cockpits and the new Ground Combat Vehicle’s interior. The last such survey was conducted in 1988.
“Everything we build that either goes on the human or the human goes in will depend on the data coming out of this study,” says Jack Obusek, director at the soldier center. “We know that the human form has changed in our population since 1988. We have to understand what that means for the Army. We can no longer base it on these ’88 standards.”
Meanwhile, the never-ending struggle to reduce loads continues.
A soldier’s size certainly will come into play when wearing HULC, a human universal load carrier being developed in conjunction with Lockheed Martin Corp. Despite the acronym, the exoskeleton is not like those seen in Hollywood movies. It doesn’t fly or shoot laser beams, and it isn’t nuclear powered.
It consists of metal leg braces that transfer weight from the soldier’s back to the ground. Lockheed officials told National Defense last year that the hydraulic-powered system can carry up to 200 pounds. A microcomputer picks up signals from sensors placed throughout the exoskeleton so that the braces mimic a soldier’s motions. It can perform deep squats, crawls and upper-body lifts without much help from its human partner.
Researchers at Natick just finished collecting data from a series of biomechanical tests with the system. The results will tell them just how much energy a soldier can conserve by wearing the HULC.
“My view of the exoskeleton is that it could help you get to the fight so you won’t get there exhausted by carrying a load on your back,” Obusek says. “But when you get to the fight you aren’t going to be fighting in the exoskeleton. You’re going to drop it and you’re going to go into battle. It has to be something you can quickly get out of should the need occur.”
Perhaps 20 or 30 years from now, exoskeletons could also help augment strength in more complex situations during actual battle, he says. Though there have been significant advances in wearable robots in recent years, the sticking point continues to be power.
An exoskeleton requires batteries, which themselves add weight to a soldier’s load, says retired Lt. Col. David Accetta, chief of public affairs at Natick. “So you’re adding weight to the system to make it easier to carry the heavy load of the batteries plus whatever else you need to carry.”
Natick officials are watching closely another kind of robot being developed just down the road by Boston Dynamics. The company is building the Legged Squad Support System, or LS3, a machine the size of a modest dining room table that soldiers can load up with 400 pounds of gear and enough fuel for a 20-mile, 24-hour-long mission.
A video online of a previous version, Big Dog, shows the robot keeping its balance on hillsides and ice and even after being physically assaulted by human beings. The LS3, which is expected to be unveiled next year, will be able to follow along with a unit or be programmed to meet troops at a certain location.
But what if soldiers could count on certain items simply being there when they reached a destination? A recent study by the Naval Research Advisory Committee determined that the solution to reducing soldier and marine loads could be cut into thirds — technology, leadership and logistics.
“We wouldn’t have a load carriage problem if I could guarantee [a soldier] that when he got to objective X everything he needed was going to be there when he got there,” Obusek says.
The use of air drops to deliver cargo in theater has increased exponentially. Last year saw 60 million pounds delivered this way, compared to a projected 100 million pounds this year.
Natick has built a steerable parachute into which soldiers can program GPS coordinates. These chutes can be made to avoid certain terrain features and carry 2,000-pound bundles. Scientists also came up with a less expensive way to deliver a lot of items at low altitudes, developing a family of throwaway polypropylene parachutes. Another concept being investigated is the use of unmanned aircraft to drop food, ammo and medical supplies into a precise area.
The weight issue has been around as long as the soldier research center.
If researchers make the load 10 pounds lighter, there is a platoon leader somewhere who is going to view that as freeing up space for the soldier to carry 10 more pounds of something else such as water or ammo, Natick officials say.
“We’ve been making lightweight stuff for 50 years here. How come we still load soldiers to 120 pounds?” Obusek says. “Because we can. There’s a leadership issue in there. I’ll keep making it lighter. I’ll keep beating my head against that wall, but someone has got to say, ‘OK. Here’s the capability we’re going out the gate with and I’m taking responsibility for the load you carry.’”
Still, scientists plug away on technology with a wide range of deadlines. Sometimes the Army needs them to deliver something to soldiers within weeks. It took a little more than a month for Natick to build an ammo carrier for a lightweight machine gun that allowed troops to have access to up to 500 rounds of ammunition — as opposed to 100 or 200.
Other times, researchers are looking decades ahead. An example of this may be their pursuit of functional fibers.
“Your shirt is woven of some kind of blend of cotton and rayon fibers that provides you minimal protection from the sun or the wind or the cold or whatever,” Obusek explains. “If we could start making those fibers to have a functionality . . . we could build that into the fiber and then weave that into the uniform. Multi-functional fibers are going to be a breakthrough area.”
Imagine fibers that can double as sensors, computers or an electrical bus that moves power around the uniform eliminating the need for heavy batteries. Natick is working with the Massachusetts Institute of Technology on these multi-tasking fabrics, which also may be able to adjust to environmental conditions. Scientists want to be able to make a uniform that can sense and respond to extreme weather conditions. That would mean fewer layers of clothing soldiers would have to carry in their rucksacks.
Natick already has the laboratory to test these “smart” fibers. The Doriot Climatic Chambers consist of two wind tunnels that are used to test the performance of both equipment and troops in extreme environments. A “tropic” tunnel can create temperatures ranging from zero to 165 degrees Fahrenheit with up to 90 percent humidity. Rain can be simulated at up to four inches per hour with wind up to 40 mph. An “arctic” tunnel can drop the temperature to negative 70 degrees Fahrenheit.
At any given time, there are a couple of dozen soldiers living in the Natick barracks. They volunteer to take part in tests and may end up doing everything from jumping around in exoskeletons to running on treadmills in the wind tunnels. They stay between 90 days and six months and can opt out of any experiment.
These volunteers are a key component to reducing the load of their colleagues in battle. They most likely will be the first to try on body armor made of lightweight nano-materials.
Scientists would like to build an armor suit no more encumbering than a t-shirt, but they have recognized that the so-called super fibers needed to do this could be decades away. So Natick is investigating what to do in the meantime.
“We know a lot about how the human behaves and how the human form has to accept body armor and be able to move and do the job,” Obusek explains. “So we take that knowledge and do a much better job at designing human-centric armor to make sure we’re covering areas where you have to move but allowing flexibility where you need it.”
This is requiring the Army to take another look at how it contours armor to the bodies of soldiers, particularly females. It also will force the service to make its armor more adaptable to different missions. Soldiers should be able to put on and take off protective pieces based on their assigned tasks and the threats involved, officials say.
By introducing new materials to soft armor and through careful study of soldier shapes, Obusek estimates that researchers can shave 6 to 10 percent of weight off the current system of body armor. That’s between 2.1 and 3.5 pounds of today’s 35-pound tactical vest.
“It remains to be seen where the further out technologies are going to take us,” he says. “We honestly don’t know.”
Topics: Land Forces