On May 21st, 2010, the Akatsuki orbiter (“Dawn” in Japanese) launched from the Tanegashima Space Center atop a H-IIA Launch Vehicle, establishing orbit around Venus in December 2015. In so doing, Akatsuki became the first interplanetary mission launched by the Japan Aerospace Exploration Agency (JAXA). For the past eight years, this mission has been continuously monitoring Venus’ atmosphere to monitor its weather patterns using four types of instruments: an ultraviolet and infrared cameras, a high-speed imager, a radio science suite, and an ultra-stable oscillator.
These have allowed Akatsuki to map clouds, detect lightning, examine the vertical structure of the atmosphere, and measure the vertical profiles of temperature and other factors. According to an announcement issued on September 18th, 2025, JAXA conducted the termination procedure for the Akatsuki mission starting at 9:00 AM JST (8:00 PM EST; 5:00 PM PST). This comes over a year after JAXA lost communication with the probe (near the end of April 2024), which occurred while the probe was place in control mode for lower-precision attitude maintenance. Since then, recovery operations have been conducted to restore communications, but these have proven ineffective.
Considering that the spacecraft has greatly exceeded its designed lifetime and was already in the late stage of its operations, JAXA has chosen to end the mission. In the eight years that Akatsuki monitored Venus’ atmosphere, the mission achieved many milestones. This included discovering the largest stationary gravity wave in the Solar System, vital data on the mechanism that maintains high-speed atmospheric circulation around Venus, and the application of meteorlogical techniques widely used on Earth to Venus for the first time.
This was in keeping with Akatsuki’s mission, which was to clarify the three dimensional motion of the Venusian atmosphere over time and establish a meteorology of Venus. “We would like to express our deepest gratitude to all the organizations and individuals who have cooperated and supported the development and operation of Akatsuki,” JAXA announced.
Further Reading: JAXA