A pair of unarmed Global Hawk surveillance drones have been deployed to Japan by the US Air Force, possibly to keep an eye on North Korea and naval operations in China. According to the Associated Press, the drones will use the Misawa Air Base in northern Japan through October, though the US government has not provided any details on the missions that will be carried out. The Global Hawk drones are made by aerospace and military contractor Northrop Grumman, and specialize in long-distance, high-altitude unmanned flights. Last year, a Global Hawk flew for more than 34 hours at altitudes of up to 60,000 feet.