The Navy's X-47B killer drone is about to get a lot more lethal. Nine months after the 38-foot-long, bat-shaped flying robot took off from Edwards Air Force Base in California for its very first flight, the Navy has announced it will add an aerial refueling capability to at least one of the two X-47 prototypes sometime in 2014.

The decision to add refueling software and equipment was published on the federal government's business opportunity website and first reported by InsideDefense. (Alas, the piece is behind a firewall.)

How big a deal is this? In a word, very.

After all, what makes the X-47B unique is the fact that it'll be the first drone to perform one of aviation's hardest maneuvers: taking off and landing on an aircraft carrier. And drones capable of taking on more gas in-flight could extend, by a huge margin, the range at which the Navy's 11 aircraft carriers can strike land and sea targets. That in turn should help the expensive flattops avoid the submarines, strike planes, ballistic missiles and other defenses that nations such as China are building specifically to threaten American carriers.

The key to this range increase is the pilot. Or, more to the point, the absence of a pilot.

Limited by a human being's endurance, a typical manned fighter can fly just 400 miles over the course of a few hours before it's time to return to base. A flying robot can do much better, observes the Center for Strategic and Budgetary Assessments, a Washington, D.C. think tank. "A carrier-based [Unmanned Combat Air System] with an unrefueled combat radius of 1,500 nautical miles or more and unconstrained by pilot physiology offers a significant boost in carrier combat capability," CSBA posited in a 2008 study.

"Indeed, with aerial refueling, a UCAS would be able to stay airborne for 50 to 100 hours — five to 10 times longer than a manned aircraft," the CSBA study continued. "With multiple aerial refuelings, a UCAS could establish persistent surveillance-strike combat air patrols at ranges well beyond 3,000 nautical miles." For those of you keeping track, that's nearly 10 times the range of today's carrier air wing.

The X-47, which the Navy wants by 2018, has been in development for nearly a decade by Northrop Grumman, builder of the Air Force's long-range Global Hawk spy drone. After a series of test flights from land bases – including its first wheels-up cruise, depicted above – in 2013 the X-47B will head out to the aircraft carrier USS George Washington for additional trials, launching and landing from the carrier's crowded, 1,100-foot flight deck.

The aerial refueling tests will follow the carrier trials. The X-47B will be fitted with both Navy-style refueling gear – a probe the refueling plane uses to "plug" into a basket suspended from the tanker – and the receptacle refueling equipment favored by the Air Force, which requires that the tanker plug its own probe into the receiving plane. Dual systems will allow the X-47B to sip gas from the Navy's carrier-based F/A-18 tankers or the Air Force's much larger KC-135s and KC-10s.

Not coincidentally, just last year Northrop scored a $33-million contract to outfit a Global Hawk as a tanker, with Air Force-style refueling gear. That means the Navy's killer drone could someday find itself taking on gas from another flying robot. A robotic tanker could further boost the attacking drone's range and, by extension, the striking power of the American fleet.

Video: Northrop Grumman