The X-47B, an unmanned combat vehicle built as a demonstration aircraft for the U.S. Navy, had its inaugural flight at California's Edwards Air Force Base on February 4, 2011.

A year later, the Unmanned Combat Air System demonstration project ended. The X-47B was just a demonstration, a proof of concept. However, the project led to the Carrier-Based Aerial Refueling ...

It is not clear what happened to Northrop’s X-47B after its successful flight, but in subsequent years, the service has developed a first-of-its-kind unmanned aerial refueler called the MQ-25 ...