experimental U.S. ocean surveillance satellite launched June 27, 1978. During its 99 days of operation, Seasat orbited the Earth 14 times daily and monitored nearly 96 percent of its oceanic surface every 36 hours. Instruments of the unmanned spacecraft, engineered to penetrate cloud cover, provided data on a wide array of oceanographic conditions and features, including wave height, water temperature, currents, winds, icebergs, and coastal characteristics. Although Seasat ceased data transmission on Oct. 9, 1978, as a result of a power failure, it achieved its primary purpose: to demonstrate that much useful information about oceanographic phenomena could be obtained by means of satellite surveillance. Data transmitted by Seasat was made available to scientists representing 23 government and academic organizations. The information was also used to aid the crews of transoceanic vessels and aircraft.