And they represent the Pentagon's most aggressive efforts to use technology to bolster brute force, as it develops fighter pilots helmets designed to see through the body of the plane, uniforms with fabric that conducts electricity, and Ironman-like exoskeletons.
In announcing a Defense Innovation Initiative last month, Defense Secretary Chuck Hagel said that in order to keep its battlefield edge, the military needs to move with the urgency of a Silicon-Valley start-up in developing breakthroughs in technologies such as robotics, autonomous systems, big data and 3-D printing.
While the U.S. has focused on fighting wars for more than a decade, he said that potential enemies have taken the time to innovate. "Countries like Russia and China have been heavily investing in military modernization programs to blunt our military's technological edge," he said.
Last week, the Navy announced a big step in that direction. For months, sailors tested a $40 million, 30-kilowatt laser mounted on the deck of the USS Ponce in the Persian Gulf. Using a video-game like controller, service members practiced taking out drones and small boats. And now the weapon, which looks like a giant telescope, is ready to take out real threats if necessary, officials said, meaning the Pentagon could soon record its first kill with a laser.
"The captain of that ship has all of the authorities necessary if there was a threat inbound to that ship," said Rear Adm. Matthew L. Klunder, chief of naval research. "To protect our sailors and Marines, we would defend that ship with this laser system."
Unlike missiles, lasers travel at the speed of light, so they hit their target almost instantaneously. Once built, their expense is essentially limited to the cost it takes to fuel it. Navy officials said the USS Ponce's laser, for example, costs 59 cents a shot, while the cost of some missiles that would perform the same attack can cost in the millions of dollars.
As long as there is power, lasers can also keep firing with an "unlimited magazine" that never needs to be reloaded, which is especially helpful for a ship at sea. The power of lasers can also be changed. A low-energy pulse may disable a drone's sensors, a maneuver known as "dazzling." Crank it up, though, and drone soon becomes fireball.
But laser beams fire dead straight and can't bend or easily change directions, so there has to be a clear line of sight to the target. And if it's raining, or even cloudy, the moisture in the atmosphere can make them less effective. Smoke and pollution can cause problems, as well.
And the enemy doesn't always attack on clear, sunny days.
"If you want to know the problem with lasers, try using a flashlight in the fog," said Loren Thompson, a defense analyst and consultant.
For years, lasers have been a key focus for many of the biggest defense contractors--including BAE Systems, Boeing, Lockheed Martin, Raytheon and Northrop Grumman. And the industry has been making advancements toward mounting them on trucks, tanks, aircraft and even drones, analysts said. In recent years, laser technology has reached a "tipping point," said Rick Hunt, director of Raytheon's Navy/Marine Corps Programs, and soon could be widespread.
"This isn't something in a Buck Rogers comic book," said Tom Captain, a vice chairman at Deloitte who leads the consulting firms aerospace and defense sector. "It's being deployed now."
As scientists and engineers make them smaller, more efficient and powerful, lasers will become a "top 10 acquisition" priority for the Pentagon within five years, predicted Ray Johnson, Lockheed Martin's Chief Technology Officer.
Boeing has developed a massive truck it calls a High Energy Laser Mobile Demonstrator for the Army with a laser designed to take out rockets, mortars and drones. During a recent demonstration, the laser targeted a dime-sized beam on the 10-inch mortar, and fried it until the mortar exploded mid-air.
It could also protect against rockets and missiles that travel even faster, officials said.
While many of the lasers in development would be used for relatively short distances, within a few years companies will start producing far more powerful weapons capable of much longer ranges, officials said.
And their precision could make them valuable in counterterrorism. Captain said he could envision the day when a drone spots a terrorist on the ground. But the terrorist happens to be next to a playground filled with kids.
You can't "fire a Hellfire missile and blow up the 50 kids on the playground," Captain said. But a laser could be quick and deadly--without the collateral damage, he said.
Developing the rules of engagement for lasers took top Pentagon officials a year, Klunder said. And he said that the Defense Department would comply with the Geneva Convention, which prohibits weapons that blind.
"We are going to honor the conventions with this laser system," Klunder said. "We're not going to use it to directly point and kill people."
The weapon is more effective, he said, when it's used to destroy the engines or sensors of ships and drones.
Patrick Wilcken, a trade and human rights researcher at Amnesty International, said that lasers should be "very strictly regulated and controlled so that it is never used against a human target where there is a risk of eye damage."
Despite the advancements, many think that lasers won't replace guns, cannons or missiles, but rather augment them.
That's a problem at a time when the defense budget is shrinking - not growing.
"The main budgetary drawback is that no one is proposing they replace existing weapons," said Thompson, the defense analyst. "They're saying why don't we have lasers, too. But it's an addition in a budget that can't grow."
That hasn't stopped companies from developing lasers, which many think will become a must-have technology for the Pentagon.
BAE Systems, for example, has showcased what it calls a Future Technology Demonstrator, a tank-like vehicle that has both a machine gun and a laser.
In other words, it can go sizzle and boom.