The flight and ground crew team of NASA's C-20A (G-III) Environmental Science Research Aircraft hosted a visit by U.S. Ambassador to Iceland Luis Arreaga June 11 during their brief mission based in Keflavik, Iceland. Pictured from left are Vince Moreno, Carlos Meza, Eric Green (Embassy Deputy Chief of Mission), Bart Henwood, Brittany Martin, Troy Asher, Roger Chao, Brian Hawkins, Ambassador Luis Arreaga, John McGrath, and Brent Minchew. Chao, Hawkins and Minchew are with NASA JPL, the remaining flight and ground crew are with NASA Dryden. (Photo courtesy of U.S. Embassy-Iceland) › View Larger Photo
NASA C-20A Wraps up Icelandic Ice Caps Survey
Following a final six-hour data collection mission June 14, NASA's C-20A (G-III) Environmental Science Research Aircraft was scheduled to depart Keflavik, Iceland, and fly back to the United States June 15 to begin another campaign with its sophisticated synthetic aperture radar.
The modified C-20A, the military version of the Gulfstream III business aircraft, and its UAVSAR radar system was scheduled to arrive at Grand Forks Air Force Base in North Dakota about mid-day Friday and begin a new mission to collect soil-moisture data in the northern plains states on June 16, weather permitting. That study is intended to aid in the development and validation of algorithms for a future soil moisture satellite mission.
The Iceland mission was hampered somewhat when the aircraft's right alternator failed and its Digital Global Positioning System (DGPS) provided some spurious navigation information during the first week. Once the alternator was replaced and flights were switched to the early morning instead of the evening, possibly allowing better GPS satellite coverage, the remaining data-collection flights were the most successful of the mission, according to Dryden's mission manager John McGrath and pilot Troy Asher, Dryden's senior representative on the deployment.
In his flight report, Asher noted that the final flight June 14 not only accomplished all 15 primary data-collection lines or tracks, but successfully collected data on three more.
"The system performed admirably all day, and we only had one very minor tracking difficulty which delayed the beginning of one line, but otherwise everything was perfect," he added.
Developed by NASA's Jet Propulsion Laboratory, the UAVSAR mounted on the aircraft's underbelly uses a technique called interferometry to detect and measure very subtle deformations in Earth's surface. The process is aided by a Dryden-developed Precision Platform Autopilot in the aircraft that enables it to repeat flight patterns over a previous flight track within 10 meters of the original flight track while flying at altitudes up to 41,000 feet.
The Iceland mission collected data to develop 3D surface velocity fields for Hofsjokull and Langjokull glacier ice caps in central Iceland, according to Dryden pilot Troy Asher. The data collected will provide insight into the yearly, seasonal, and daily variations of the glacier velocity and improve the understanding of the physics of a glacier flow.
During the 12-day Icelandic campaign, the flight and science team hosted a visit by the U.S. Ambassador to Iceland, Luis Arreaga. The mission was also featured on Icelandic Television's news program, including an interview with acting principal investigator Brent Minchew, a graduate student at the California Institute of Technology.
-- Alan Brown, Public Affairs
NASA Dryden Flight Research Center