130517-N-YZ751-017 ATLANTIC OCEAN (May 17, 2013) An X-47B unmanned combat air system (UCAS) demonstrator conducts a touch and go landing on the flight deck of the aircraft carrier USS George H.W. Bush (CVN 77). This is the first time any unmanned aircraft has completed a touch and go landing at sea. George H.W. Bush is conducting training operations in the Atlantic Ocean. (U.S. Navy photo by Mass Communication Specialist 2nd Class Tony D. Curtis/Released). MC2 Tony D. Curtis

The X-47B autonomous aircraft made history last week, successfully landing on the aircraft carrier George H. W. Bush. Twice. Then things went awry. A third aircraft carrier landing attempt that same day was aborted, and on Monday a fourth and final aircraft carrier landing was halted before it could even be attempted. The future of naval aviation isn’t ready for the future just yet.

What happened? The first failure was a computer error, detected by the X-47B itself, which the machine caught before attempting the landing. The aircraft’s three navigational computers couldn’t all agree on the right course of action, so they decided the X-47B couldn’t land safely on the carrier. The X-47B then checked in with the humans in charge, and plotted a course to a safer landing (on land). The second and more recent failure–on a separate X-47B aircraft–is attributed to unspecified technical issues while flying out to the aircraft carrier.

The two X-47Bs, awesomely named Salty Dog 501 & 502 (possibly after the delicious drink?) are set to retire soon. The two completed landings show that the technology has tremendous potential for the future. Tomorrow’s autonomous aircraft, informed by research conducted in the X-47B program, will fly ahead and scout for carrier fleets, for up to a day at a time, and finally return safely to refuel before doing it again.

The two aborted landings, more than anything else, show that a brand-new experimental technology is not yet ready for prime time. If the X-47B were a military aircraft about to be pressed into service, this would be a problem. But the X-47B is a technological testbed, whose failures teach researchers just as much as the successes.