The U.S. Air Force awarded Northrop Grumman Corp. a $490 million contract to build its Global Hawk autonomous spy aircraft for Japan.

Northrop Grumman (NYSE: NOC) builds the aircraft in Palmdale but runs the program in San Diego. Japan is buying three Block 30 Global Hawk aircraft, as well as two ground control elements, spares and support equipment. The deal also covers system engineering and program management.

The U.S. Air Force is handling the foreign military sale. In October 2017, the Air Force awarded Northrop Grumman a preliminary, $130.5 million contract for components that take a long time to manufacture.

The Air Force made the most recent award on Nov. 20, and work will last through 2022.