EQUATOR-S: The mission and first coordinated measurements with GEOTAIL Original Research Article

An overview of the origin of the EQUATOR-S mission, the spacecraft development and the mission history is given. In spite of its short operational life of only five months, the major goals were fulfilled, except that its contribution to IASTP science is restricted to the morning sector of the outer magnetosphere. A few data sets illustrating the satelliteʹs capability are presented.