MechWarrior was a popular game back in the Stone Age.

We’re inching our way toward it now.

Of the many risks dismounted Soldiers face in the field, one of the most common is injury from carrying their gear—often topping 100 pounds—for extended periods over rough terrain. Heavy loads increase the likelihood of musculoskeletal injury and also exacerbate fatigue, which contributes to both acute and chronic injury and impedes Soldiers’ physical and cognitive abilities to perform mission-oriented tasks. To help address these challenges, DARPA seeks performers for the last phase of its Warrior Web program.

Warrior Web aims to develop a soft, lightweight undersuit that would help reduce injuries and fatigue and improve Soldiers’ ability to efficiently perform their missions. The garment would protect injury-prone areas and promote efficient and safe movement over a wide range of activities (walking, running, jumping, crawling, etc.). Comfortable, durable and washable, the garment would not interfere with body armor or other standard clothing and gear. DARPA seeks to create a working prototype that significantly boosts endurance, carrying capacity and overall Soldier effectiveness—all while using no more than 100 watts of power.

“Many of the individual technologies currently under development show real promise to reduce injury and fatigue and improve endurance,” said LTC Joseph Hitt, DARPA program manager for Warrior Web. “Now we’re aiming to combine them—and hopefully some new ones, too—into a single system that nearly every Soldier could wear and would provide decisive benefits under real-world conditions.”

The decreased mobility, shortened endurance, and much higher risk of injury imposed by the extraordinary loads today’s infantry must carry have made them far less effective, in the close fight than in the past. This is, of course, offset to some extent by the much greater survivability provided by the modern body armor, and by increases in their sensors and targeting capability.

The key hurdle for any such exoskeleton system is power. How to power the system without the battery or other source becoming an even greater burden, either directly on the soldier or simply on the logistical pipeline, has been the biggest challenge.

I think we’re a long, long way from seeing a practical system fielded throughout the force, but the progress made in the last decade is pretty impressive, for relatively modest sums of money.

Beyond GPS for JDAM

The Joint Direct Attack Munition, the GPS/Inertial guidance kit that transforms a dumb bomb into a smart bomb has been a smashing success. And it is only one of many GPS guided weapons in the inventory today. The problem is, GPS guidance relies on an external source of information, that is, the constellation of GPS satellites.  GPS is jam-resistant, but not jam proof. Since the early days of the GPS program, the fear has been that sooner or later, someone would be able to consistently jam the signal. 

Not surprisingly, DARPA, the Defense Advanced Research Projects Agency, would like to develop an alternative to the reliance on GPS that current technology provides

I’m not exactly bright enough to delve into the technical aspects of “Chip-Scale Combinatorial Atomic Navigator (C-SCAN)” but I do understand the basics of inertial navigation. Originally using gyroscopes and precession to measure the movement of a platform, most Inertial Navigation Systems today use ring-laser gyros today that use doppler shift in the laser light to measure displacement. And if you know how much a platform is displaced from its starting point, that is, the sum of all accelerations (and decelerations, which are just accelerations in a different direction), you can compute the current location (and velocity) of the platform. 

But INS systems tend to have significant drift errors accumulating over time. Today, most INS systems update from time to time with GPS. That means that even if the GPS is unavailable, the INS platform provides at least some level of navigation capability.  For instance, the JDAM is always labeled as GPS guided, but in actuality, it has an INS guidance system with GPS updates.

If DARPA can work with industry to build a small, reliable system that is completely free of external input, the potential vulnerability of our current generation of GPS assisted weapons would be erased. Other applications on the battlefield, such as Blue Force Tracker systems would also be enhanced.