First it was missiles, and now the US Navy can add unmanned drones to the list of things that can be launched from a submerged submarine. The Navy today announced that it did just that in a recent demonstration that took some six years to develop. The drone, called an XFC UAS-eXperimental, was launched in a standard torpedo tube from the Navy's USS Providence using a similar technique to how the Navy deploys Tomahawk cruise missiles.

The test launch was followed by what the Navy says was a successful, "several hour" flight. The XFC itself can last for more than six hours on fuel cells, and be launched from something as small as a pickup truck when on land, the Navy says.

The launch comes amid intensified interest in the use of drones in commercial applications. Amazon last week announced plans to offer same day delivery on some goods using short-range drones. The world's largest parcel service, UPS, is also researching the use of drones for delivering some packages.