How technology could create 'super soldiers'.

• Author: Harper, Jon

Popular culture has long been fascinated by the idea of enhancing human beings. From the 1970s TV show "The Six Million Dollar Man" to this year's latest "Captain America" film, sci-fi writers have imagined what it would be like to give individuals extraordinary powers.

In the real world, scientists and engineers are working on a number of cutting-edge technologies to make U.S. troops faster, smarter and more resilient than their normal selves.

Paul Scharre, a former Army Ranger and the director of the 20YY Future of Warfare Initiative at the Center for a New American Security, said performance-enhancers that are being explored could offer tremendous operational advantages for warfighters.

"What if we had an 'on' switch right before pilots were about to go into a dogfight and we could turn that switch on? Or right before infantry soldiers were about to go into combat we could turn that switch on? That would have profound... implications for warfare," he said.

Sometimes referred to as human enhancement or human augmentation, the effort to create what observers have called "super soldiers" is progressing on many fronts.

In one example, the Defense Advanced Research Projects Agency has launched 4MM, a project to develop a device that could enable dismounted troops to run a four-minute mile, a benchmark normally reserved for the world's most elite runners.

"The underlying theory there is if you can provide some forward push to... the wearer, can you make it so they can run faster," said Mike LaFiandra, chief of the dismounted warrior branch in the human research and engineering directorate at the Army Research Laboratory, where 4MM prototypes have been tested. "There are different concepts for how that forward push comes."

With DARPA funding, researchers at Arizona State University developed a system called Air Legs.

"We built an exoskeleton... where we used air cylinders that would move back and forth very quickly to allow people to run fast," said Tom Sugar, a professor in ASU's department of engineering. "We had people running as fast as 5.5 meters per second or 12 miles an hour."

Sustained running at that speed would enable a soldier to clock a five-minute mile. A runner would need to reach speeds of 15 miles per hour or greater to achieve a four-minute mile.

LaFiandra said the project is "progressing" and additional prototype evaluations will be conducted this fall.

To enable troops to essentially be smarter, scientists at the Air Force Research Laboratory are exploring the implications of transcranial direct current stimulation, or TDCS. The process entails attaching electrodes to a person's head and passing a low-intensity electrical current to the brain.

"We are seeing...