This 2012 NASA photo obtained August 20, 2014 shows NASA's Global Hawk No. 871 as it cruises over low cloud layers above the Dryden Flight Research Center on Edwards Air Force Base, California. This was the first Global Hawk built in the original Advanced Concept Technology Demonstration program, joining NASA's other Global Hawk, No. 872, for high-altitude, long-endurance environmental science missions. A pair of converted military drones are the US space agency's newest tools for tracking hurricanes and tropical storms, with the aim of improving forecasters' ability to predict them. Originally built for military reconnaissance missions around the world, they are the size of large commercial jets and are flown remotely from a NASA base on the Virginia coast. The drones are capable of flying for 30 hours at an altitude of 21,000 meters (69,000 feet), or twice the height of a passenger plane. They can also cover large swaths of the Pacific and Atlantic Oceans in a single mission, according to Chris Naftel, head of the drone project at NASA's Dryden center in California, the secondary drone base. The two Global Hawks began operating as NASA drones in 2012, as part of a project that will last for three years. The drones operate in most active months -- August and September -- of the Atlantic hurricane season, which goes from June to the end of November. "It opens a window into a storm we did not have before," said Scott Braun, a research meteorologist on the project called HS3, short for the Hurricane and Severe Storm Sentinel. AFP PHOTO/NASA/LORI LOSEY/HANDOUT = RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / NASA/LORI LOSEY/ HANDOUT" - NO MARKETING NO ADVERTISING CAMPAIGNS - NO A LA CARTE SALES/DISTRIBUTED AS A SERVICE TO CLIENTS = / AFP PHOTO / NASA / Handout