The Hisaki satellite is equipped with an extreme ultraviolet spectrograph and is the world’s first space telescope designed for planetary observations. By observing the time variable aspects of atmospheres of terrestrial planets such as Venus and Mars, and hot plasma in the Jovian magnetosphere, Hisaki provided opportunity to study the atmospheric evolution of terrestrial planets in the Solar System and the origin of mass and energy in Jupiter’s magnetospheric plasma. The Hisaki satellite was launched on 14 September 2013. Aft¬er more than 10 years of continuous extreme ultraviolet spectroscopic observations, the satellite was decommissioned on 8 December 2023.