As L.A. Times says about the X-47B:
"...It's designed to land on the deck of an aircraft carrier, one of aviation's most difficult maneuvers.
What's even more remarkable is that it will do that not only without a pilot in the cockpit, but without a pilot at all...
The drone is slated to first land on a carrier by 2013, relying on pinpoint GPS coordinates and advanced avionics. The carrier's computers digitally transmit the carrier's speed, cross-winds and other data to the drone as it approaches from miles away.
The X-47B will not only land itself, but will also know what kind of weapons it is carrying, when and where it needs to refuel with an aerial tanker, and whether there's a nearby threat, said Carl Johnson, Northrop's X-47B program manager. "It will do its own math and decide what it should do next."
Funded under a $635.8-million contract awarded by the Navy in 2007, the X-47B Unmanned Combat Air System Carrier Demonstration program has grown in cost to an estimated $813 million."