The experimental, carrier-based drones that Northrop Grumman Corp. built for the U.S. Navy are getting an extension of what was to be short service lives.

The Navy said on June 26 that it awarded Northrop Grumman (NYSE: NOC) a $63.1 million contract to support its two X-47B aircraft through March.

Among other things, the funds will pay for maintenance support and continued flight test opportunities.

Seventy percent of the work will be carried out in Rancho Bernardo — the center for Northrop Grumman’s unmanned aircraft work — while 30 percent will be carried out in Patuxent River, Md., which is the headquarters of Navy aviation. The Naval Air Systems Command of Patuxent River awarded the contract.

The X-47B is a carrier-sized aircraft without a tail that first flew in 2011. It has performed catapult takeoffs and arrested landings on aircraft carrier decks.

Shares of Virginia-based Northrop Grumman closed June 26 at $120.40, close to its 52-week high of $126. The lowest that shares dropped during the last 52 weeks was $81.34.