GEOTAIL Mission
In order to investigate the geomagnetic tail region of the magnetosphere, the Institute of Space and Astronautical Science of Japan (ISAS) and
the United States National Aeronautics and Space Administration (NASA) agreed to undertake a joint project to develop, launch, and operate
a scientific satellite designated the GEOTAIL satellite. The GEOTAIL mission measures global energy flow and transformation in the magnetotail
to increase understanding of fundamental magnetospheric processes, including the physics of the magnetopause, the plasma sheet, and reconnection
and neutral line formation. These objectives require spacecraft measurements in two orbits: a nightside double lunar swingby geotail orbit to
distances of 220 Re and a low inclination orbit at geocentric distances of about 8 to 30 Re. The GEOTAIL satellite was designed and developed
by ISAS, and it was launched by NASA by DELTA II expendable launch vehicle on 24 July 1992. It includes scientific instruments provided by ISAS
and NASA. The satellite was placed into the initial distant tail orbit for approximately two and a half years until November 1997; thereafter, it was
maneuvered into a near-Earth orbit of 10x30 Re that was slightly reduced in June 1997 to a final orbit of 9x30 Re.
Together with the WIND, POLAR, SOHO and CLUSTER projects, GEOTAIL constitutes a cooperative scientific satellite project of ISAS, NASA and
the European Space Agency (ESA) designated the International Solar Terrestrial Physics, or ISTP, Program
(artist's rendition)
which aims at gaining improved understanding of the physics of the solar terrestrial relations. The Space Research Institute (IKI) of
the former Soviet Union will also launch INTERBALL and RELICT-2 satellites in the same time frame, and the entire program is coordinated
by the Inter Agency Consultative Group for Space Sciencd (IACG).
