A drone the size of a fighter jet has taken off from the deck of an US aircraft carrier for the first time in a test flight that could eventually open the way for the US to launch unmanned aircraft from almost anywhere in the world.
The X-47B is the first drone designed to take off and land on a carrier, meaning the US military would not need permission from other countries to use their bases.
Developed by Northrop Grumman under a 2007 contract at a cost of $1.4bn, the X-47B is capable of carrying weapons and providing around-the-clock intelligence, surveillance and targeting, according to the navy, which has been giving updates on the project over the past few years.
The move to expand the capabilities of the nation's current drones comes amid growing criticism of Washington's use of Predators and Reapers to gather intelligence and carry out lethal missile attacks in Iraq, Afghanistan, Pakistan and Yemen.
Critics in the US and abroad have charged that drone strikes cause widespread civilian deaths and are conducted with inadequate oversight. Defence analysts argue drones are the future of warfare.
James Lewis, senior fellow at the Centre for Strategic and International Studies in Washington, said the new Joint Strike Fighter jet "might be the last manned fighter the US ever builds.
"They're so expensive, they're so complex, and you put a human at risk every time it takes off from a carrier."
While the X-47B is not intended for operational use, it will help navy officials develop future carrier-based drones.
"The big public display is to build support for this program, to make sure that we follow through on it and that we're willing to spend the money," Lewis said.
"If Congress pulls the plug on this it will set the navy back a decade."
Operational in 2020
The drones could begin operating by 2020, according to Rear Admiral Mat Winter, the navy programme's executive officer for unmanned aviation and strike weapons.
The X-47B is far bigger than the Predator, the drones generally used by the US at the moment, has three times the range, and can be programmed to carry out missions with no human intervention, the navy said.
While the X-47B is not a stealth aircraft, it was designed with the low profile of one.
That will help in the development of future stealth drones, which would be valuable as the military changes its focus from the Middle East to the Pacific, where a number of countries' air defences are a lot stronger than Afghanistan's.
During Tuesday's flight, the X-47B used a steam catapult to launch, just as traditional navy warplanes do.
The unarmed aircraft then landed at Naval Air Station Patuxent River in Maryland.
The next critical test for the tailless plane will come this summer, when it attempts to land on a moving aircraft carrier, one of the most difficult tasks for navy pilots.
Earlier this month, the X-47B successfully landed at the air station using a tailhook to catch a cable and bring it to a quick stop, just as planes setting down on carriers have to do.
The X-47B has a wingspan of about 19 metres and weighs 6,350 kilogrammes, versus nearly 15 metres and about 499 kilogrammes for the Predator.
While Predators are typically piloted via remote control by someone in the US, the X-47B relies only on computer programmes to tell it where to fly unless a human operator needs to step in.
Eventually, one person may be able to control multiple unmanned aircraft at once.
The X-47B can reach an altitude of more than 12,192 metres and has a range of more than 3,890km.
The navy plans to show the drone can be refuelled in flight, which would give it an even greater range.