NASA's Global Hawk No. 871 cruises over low cloud layers above the Dryden Flight Research Center on Edwards Air Force Base, Calif.NASA/Lori Losey
NASA Goddard's Cloud Physics Lidar electronics are installed in the upper area of NASA's Global Hawk unmanned aircraft just in front of the aircraft's communications antenna.NASA/Tom Tschida
Technicians prepare to install the High-Altitude Imaging Wind and Rain Profiler, or HIWRAP, on the underside of a NASA Global Hawk. HIWRAP is one of the science instruments being carried by the remotely operated high-altitude aircraft during the Hurricane and Severe Sentinel missions.NASA/Tony Landis
Autonomous drones will be used as storm chasers off the U.S. East Coast this month.
NASA is deploying two Global Hawks acquired from the U.S. Air Force on the Hurricane Severe Storm Sentinel Mission, or HS3, kicking off this year.
September is the peak Atlantic hurricane month so these Unmanned Aerial Vehicles (UAVs) will be studying storms at their height. Referred to as "severe storm sentinels,” the Global Hawks will be flying out of NASA Wallops Flight Facility in Virginia.
The five-year Hurricane and Severe Storm Sentinel mission is investigating the processes that influence hurricane formation and intensity change in the Atlantic Ocean.
In the past, advances have been restricted by the limited number of storms to sample, the distance of storms from the operating base and the difficulty in obtaining them.
Hurricanes are an extreme environment making them very difficult to sample. Between heavy precipitation; high winds and turbulence in the air; and heavy seas on the ground, storm chasing can be a dangerous business. Using unmanned aircraft keeps humans out of risk.
With other remotely operated or robotic aircraft, piloted aircraft or space satellites it can be very challenging to monitor remote extreme locations like a hurricane.
With a single Rolls-Royce AE3007H turbofan engine, these drones can fly at altitudes greater than 60,000 feet, with an 11,000-nautical-mile range, for approximately 30 hours -- letting them cover thousands of square miles over a storm.
The Global Hawk is 44-foot-long with a wingspan more than 116-feet wide, though the craft is just 15 feet high.
The drones are flown by pilots in ground control stations at NASA's Wallops Flight Facility in Wallops Island, Va., and NASA's Dryden Flight Center on Edwards Air Base, Calif.
Manning the helm works just like auto pilot in a regular, piloted plane. Headings and altitudes are put into the flight computer, and then the Global Hawk processes and executes the commands. The pilot can intervene at any time if the mission requires.
Using cameras, the pilot can get an idea of where they are flying and the storm scope helps identify lightening risks.
During missions, dedicated satellite communication links give the researchers direct access to onboard equipment and the ability to monitor instruments and data in real-time from the ground control station.
Two further key advantages to deploying Global Hawk include the autonomy and ability to carry a very heavy payload at 1,500-pound.
Each Global Hawk has three payloads with one focused on the environment and the other on the inner-core structure.
While NASA’s Global Hawks may look similar to the military ones, the payloads are very different. The first Global Hawk is charged with sampling the hurricane’s environment, for example.
In the nose will be the Cloud Physics Lidar (CPL) laser system to measure cloud structure and dust, sea salt and smoke particles. It does this by bouncing laser light off the clouds and particles.
The Scanning High-resolution Interferometer Sounder, an infrared instrument designed by the University of Wisconsin in Madison, is embedded in the belly. It measures the temperature, vertical water vapor and sea surface temperature.
The third is the dropsonde system from the National Center for Atmospheric Research and National Oceanic and Atmospheric Administration.
Located in the tail of the aircraft, the dropsonde system holds up to 88 little canisters and ejects these small sensors like a Coke dispenser. Each sensor has a parachute that allows it to float through the storm while measuring data like pressure, humidity and temperature and using GPS. They transmit data in real time back to the home base.
The second Global Hawk’s key responsibility is to sample hurricane cores.
Located in the nose, NASA's Jet Propulsion Laboratory created a microwave system, the High-Altitude MMIC Sounding Radiometer, to measure temperature, vertical precipitation and water vapor.
In the belly, a High-altitude Imaging Wind & Rain Airborne Profiler radar system works like a ground radar system but is pointed down to measure cloud structure and winds.
In the tail section, the Hurricane Imaging Radiometer will measure microwave radiation to analyze surface wind speeds and rain rates.
If you would like to storm chase from the comfort of your own home, you can follow the flight schedules on the mission website.
Ballet dancer turned defense specialist Allison Barrie has traveled around the world covering the military, terrorism, weapons advancements and life on the front line. You can reach her at firstname.lastname@example.org or follow her on Twitter @Allison_Barrie