This is an excerpt from EERE Network News, a weekly electronic newsletter.

October 23, 2002

Solar-Powered Aircraft Successfully Surveys Coffee Fields

For most people, the only connections between the sun and coffee are that the former helps the latter grow, and they are both welcome sights in the morning. But thanks to scientists at the National Aeronautics and Space Administration (NASA), the sun may now have a role in determining when coffee growers should harvest their fields.

In a test of remote sensing from uninhabited aerial vehicles (UAVs), NASA's solar-powered and remote-controlled Pathfinder Plus airplane hovered for four hours over the island of Kauai on September 30th, relaying 300 high-resolution images of the island's largest coffee plantation to the ground. Despite clouds covering as much as 80 percent of the plantation, the airplane was able to fly over clearings in the clouds and photograph virtually all of the coffee fields. At one point, the aircraft was even controlled by a researcher in California. The photos were provided to the plantation's harvest manager, who can judge the ripeness of the coffee beans in each field by the color. Unfortunately, bad weather limited the test to only a single flight. See the press release from the NASA Ames Research Center.

Stan Herwitz, a professor of earth science at Clark University, is the principal investigator for the project. Images of the airplane and the coffee fields, as well as a mission log and other information, are available on his Clark University Web site.

Future UAVs may be powered by fuel cells, thanks to the Boeing Company. Boeing announced in early September that the Defense Advanced Research Projects Agency had awarded the company a contract to develop a fuel-cell-based propulsion system for UAVs that will allow them to fly for extended periods of time. See the Boeing press release.