The GEOTAIL mission is a collaborative project undertaken by the Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), and the National Aeronautics and Space Administration (NASA). The Geotail spacecraft was designed and built by ISAS and was launched on July 24, 1992. After fulfilling Its original objective of studying the dynamics of the Earth's magnetotail over a wide range of distances, extending from the near-Earth region, roughly eight Earth radii (Re) from the Earth to the distant tail about two hundred Re, its orbit was changed.
Since February 1995 Geotail has been in an elliptical nine by thirty Re orbit where it has provided data on most aspects of the solar wind interaction with the magnetosphere. The spacecraft contains a magnetic field monitor, an electric field monitor, two plasma monitors, two sets of high-energy particle monitors and a plasma wave instrument.