It took six years to develop and launch an all-electric, fuel cell-powered, folding-wing drone aircraft from a submerged submarine. The eXperimental Fuel Cell Unmanned Aerial System, or XFC UAS, was fired from the submarine's torpedo tube using a “Sea Robin” launch system, which is designed to fit within an empty Tomahawk launch canister used for launching Tomahawk cruise missiles.

 

The XFC UAS uses an electrically assisted take-off system which lifts the plane vertically out of its container. Once deployed from the submarine, the Sea Robin launch vehicle rose to the ocean surface where it appeared as a spar buoy.