The Japan Aerospace Exploration Agency (JAXA) conducted the termination procedure for the Venus Climate Orbiter “Akatsuki” (PLANET-C) starting at 9:00 AM on September 18, 2025 (JST), thereby ending the probe's operations.Akatsuki was launched from the Tanegashima Space Center on May 21, 2010, aboard the H-IIA Launch Vehicle No. 17. The spacecraft successfully entered Venus orbit in December 2015, becoming Japan's first planetary orbiter beyond Earth. Since then, Akatsuki continuously observed Venus's atmosphere for more than eight years. The mission’s scientific achievements focussed on planetary meteorology and included the discovery of the largest mountain wave (stationary gravity waves) in the Solar System, the elucidation of the mechanism that maintained high-speed atmospheric circulation (super-rotation) around Venus, and the application of data assimilation techniques (popular in Earth's meteorological research) to Venus for the first time.Communication with “Akatsuki” was lost during operations near the end of April 2024, triggered by an incident in a control mode of lower-precision attitude maintenance for a prolonged period. Although recovery operations were conducted to restore communication, there has been no luck so far. Considering the fact that the spacecraft has aged, well exceeding its designed lifetime, and was already in the late-stage operation phase, it has been decided to terminate operations.
