Electron temperature measurements carried out by Japanese scientific satellites

Electron temperature probes have been installed in five Japanese scientific satellites, starting with satellite TAIYO which was launched in 1975 to satellite AKEBONO launched in 1989. We describe here our unique electron temperature probes which were installed in these Japanese satellites and briefly overview the mission objectives and misson lives of these satellites. Several geophysical contributions made by these satellites are summarized. Typical examples of the results are presented such as anisotropy of electron temperature, temperature structure inside plasma bubbles and electron temperature around field aligned currents in the polar region. Finally we will discuss our possible contribution to IRI model.