NASA'sunpiloted Global Hawk aircraft drone has successfully completed its firstscience flight over the Pacific Ocean.
Theflight, the first of five scheduled for this month, is part of the GlobalHawk Pacific (GloPac) mission, intended to study atmospheric science overthe Pacific and Arctic oceans.
NASA?sGlobal Hawkis a robotic plane that can fly autonomously to altitudes above 60,000 feet(18.3 kilometers) — roughly twice as high as a commercial airliner — and as faras 11,000 nautical miles (20,000 kilometers) — half the circumference of Earth.
InWednesday's flight, the plane flew approximately 4,500 nautical miles (8,300kilometers) along a flight path that took it from Dryden to just south ofAlaska's Kodiak Island, at 150.3 degrees West longitude and 54.6 degrees NorthLatitude.
Theflight lasted a total of 14.1 hours, and the plane reached heights of up to60,900 feet (18.6 kilometers) in altitude.
Theaircraftsystem carries 11 instruments to sample the chemical composition of Earth'stwo lowest atmospheric layers, to profile the dynamics and meteorology of both,and to observe the distribution of clouds and aerosol particles. Projectscientists hope to take observations from the equator to the Arctic Circle, andalso west of Hawaii.
"TheGlobal Hawk is a fantastic platform because it gives us expanded access to theatmosphere beyond what we have with piloted aircraft," said David Fahey,co-mission scientist and research physician at NOAA's Earth System ResearchLaboratory in Boulder, Colo. "We can go to regions we couldn't reach or goto previously explored regions and study them for extended periods that areimpossible with conventional planes."
Self-piloting
NASApilots and flight engineers, working with colleagues from the National Oceanicand Atmospheric Administration (NOAA), pre-program a flight path, after whichthe Global Hawk flies itself for up to 30 hours, staying in contact throughsatellite and line-of-site communications to the ground control station atNASA's Dryden Flight Research Center in California's Mojave Desert.
Theaircraft can take off, fly its mission and land without any pilot or scientistintervention. Though the plane is designed to fly on its own, pilots can changecourse or altitude based on the atmospheric conditions. Researchers have the abilityto command and control their instruments from the ground.
"TheGlobalHawk is a revolutionary aircraft for science because of its enormous rangeand endurance," Paul Newman, co-mission scientist for GloPac and anatmospheric scientist from NASA's Goddard Space Flight Center in Greenbelt, Md,said in a statement. "No other science platform provides this much rangeand time to sample rapidly evolving atmospheric phenomena."
Themission is also an opportunity to demonstrate the unique capabilities of theGlobal Hawk, while also gathering atmospheric data in a region that hasuntil now been poorly sampled, he added.
GloPacresearchers will measure and sample greenhouse gases, ozone-depletingsubstances, aerosols, and constituents of air quality in the upper troposphereand lower stratosphere.
GloPacflights should also allow scientists to observe the breakup of the polarvortex, a large-scale cyclone that dominates winter weather patterns around theArctic and is especially important for understanding ozone depletion in theNorthern Hemisphere.
Sampling the atmosphere
Researchershave already gathered some measurements from the polar vortex from Wednesday'sflight.
Scientistsalso expect to gather data between 45,000 and 65,000 feet (almost 14,000 and20,000 meters), where many greenhouse gases and ozone-depleting substances aredestroyed. This will help researchers measure dust, smoke and pollution thatcross the Pacific from Asia and Siberia that affect U.S. air quality.
Severalinstruments will measure aerosols, which play an important but incompletelyunderstood role in Earth's energy budget. Some aerosols absorb warmingsunlight, while others reflect it back to space and cool the planet. High-altitudeparticles can serve as nuclei for the formation of clouds.
GloPacwill make several flights directly under the path of NASA's Aura satellite andother Earth-observing satellites, "allowing us to calibrate and confirmwhat we see from space," Newman said. GloPac missions are being conductedin conjunction with NASA's Aura Validation Experiment (AVE).
Duringits first science flight, the Global Hawk flew under the Cloud-Aerosol LIDARand Infrared Pathfinder Satellite Observation (CALIPSO), a joint project ofNASA and France's Centre National d'Etudes Spatiales.
TheGlobal Hawk was originally flown in the Advanced Concept TechnologyDemonstration program sponsored by the DefenseAdvanced Research Projects Agency. Two test models were transferred fromthe U.S. Air Force to NASA in 2007, and a third was transferred in 2009.
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