A Japanese satellite launched by NASA in July 1992 to observe the tail of the Earth's magnetosphere. The instruments included two sets of plasma instruments and two sets of high-energy particle instruments. Geotail was the first satellite launched under the International Solar Terrestrial Physics (ISTP) programme involving the USA, Europe, Russia, and Japan. Japan's Institute of Space and Astronautical Science (ISAS) developed the spacecraft and provided about two-thirds of its scientific instruments while NASA contributed about one-third. Geotail is operated from ISAS and its data are received by both ISAS and NASA.