The National Aeronautics and Space Administration has selected two research proposals to demonstrate the capabilities of uninhabited, high-altitude aircraft as aerial platforms for Earth science and commercial applications.

The two missions, announced last week by NASA's Earth Science Enterprise in Washington, D.C., both specify use of remotely operated uninhabited aerial vehicles (UAV) which were matured under the Environmental Research Aircraft and Sensor Technology (ERAST) project at NASA's Dryden Flight Research Center, Edwards, Calif.

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau. Photo: NASA-DFRC

The first proposal, developed by Dr. Stanley Herwitz of Clark University, Worcester, Mass., would use the Pathfinder-Plus solar-powered aircraft to aid Hawaiian coffee growers by providing the growers with spectral (or color) images of their crops. From this information, the growers will know, down to the day, the best time for harvesting the beans, bringing the best flavor to consumers.

The second mission, proposed by Richard Blakeslee of NASA's Marshall Space Flight Center, Huntsville, Ala., will utilize the Altus UAV for research missions to better understand how lightning forms and dissipates during thunderstorms.

The two proposals selected for funding were among 45 originally submitted to NASA's Office of Earth Science in response to a NASA Research Announcement last year. The list was pared to 11 finalists last August, and Dr. Ghassem Asrar, NASA Associate Administrator for Earth Sciences, made the final selections last week.

As part of NASA's UAV-based science demonstration program, these demonstration flights will show the ability of this type of aircraft to carry Earth-viewing payloads in long-duration missions at altitudes exceeding the endurance of a pilot in a traditional aircraft. These capabilities will benefit both U.S. scientific and commercial objectives, with the Pathfinder-Plus coffee imaging study demonstrating the commercial application of UAVs, while the Altus missions will focus on scientific research capabilities of the craft.

The Pathfinder-Plus, a slow-moving solar-electric flying wing developed by AeroVironment, Inc., of Monrovia, Calif., currently holds the world's altitude record for propeller-driven craft of more than 80,200 feet, set in 1998 during a NASA-sponsored flight near Hawaii.

The Altus, developed by General Atomics Aeronautical Systems, Inc., of San Diego, Calif., is a civil variant of the firm's RQ-1A Predator military reconnaissance UAV operated by the U.S Air Force.

The San Gabriel range is visible as the the remotely piloted Altus 2 flies over Southern California's high desert. Photo: NASA-DFRC

It demonstrated the ability to fly at 55,000 feet altitude for four hours during a series of test flights over the Edwards Air Force Base test range in 1999. The Altus has also been the airborne platform for a series of cloud radiation studies conducted by Sandia National Laboratory for the Department of Energy in Oklahoma and Hawaii in recent years.

The coffee harvest researchers will use the Pathfinder-Plus to loiter for long periods over crop fields during the harvest season. Coffee is the leading agricultural commodity traded on world markets, and Hawaiian coffee is some of the finest in the world. A key to producing excellent coffee is knowing the right time to harvest the beans. The research team hopes the craft's unique capability will provide data the growers can use to select the best time to harvest the beans.

After flights over the Kauai Coffee Company plantation, the largest coffee plantation in America, the research team will brief coffee industry officials on its findings. The demonstration will allow NASA to provide sound science to a multi-billion dollar American industry, and is just one potential agricultural-management application using UAVs.

The Altus missions will be conducted in restricted airspace over Florida near NASA's Kennedy Space Center. When a developing storm is spotted, researchers from the University of Alabama at Huntsville, with colleagues from NASA's Goddard Space Flight Center, Greenbelt, Md., will send the Altus above and around the storm, gauging the various elements that unleash the fury of storms, while the remote pilots remain safely on the ground.

Using precision instruments aboard the aircraft, researchers will take measurements to determine lightning potential of the storms in the hopes of better understanding how different physical characteristics in the atmosphere can contribute to development of lightning. These data will increase understanding of lightning and storms, while providing federal, state and local governments new disaster-management information for use in the areas of severe storms, floods and wild fires.

The two demonstration missions are "both scientifically exciting and commercially appealing," Dr. Asrar said. "While validating this new breed of aircraft we're also providing sound science with real-world, practical applications to the American people."

The two proposals selected for funding met the NASA requirement that the missions be managed in "Principal Investigator" mode: Each mission's lead investigator is responsible for choosing the UAV best suited for the experiment, and then managing all aspects of the mission for NASA. NASA has identified approximately $8 million to fund the two UAV demonstration missions over a period of four years, with funding split roughly equally between the two proposals.

The missions are part of NASA's Earth Science Enterprise, a long-term research effort aimed at understanding how human-induced and natural changes affect our global environment, while providing practical societal benefits to America today. The Earth Science Enterprise provides the sound science needed by policy and economic decision-makers to assure responsible stewardship of the global environment.