Japanese Space agency JAXA officially announced conduct of the termination procedure of their Venus Climate Orbiter “Akatsuki” (PLANET-C) on Thursday, September 18th, 2025, thereby ending humanity’s only active Venus-circling probe’s operations. Akatsuki was launched from Japan’s Tanegashima Space Center on May 21st, 2010, aboard the H-IIA Launch Vehicle No. 17. After launch, the craft had to overcome a malfunction in its main engine, and it successfully began circling around Venus in December 2015.
Akatsuki had completed its regular two-year operation that started in April 2016, after which its operation was extended to another three-year period as there still remained fuel for controlling its attitude. During its lifetime, Akatsuki continuously observed Venusian atmosphere, weather systems, volcanic activity for more than eight years.
Communication with “Akatsuki” was lost in the end ofApril 2024, at a time when the spacecraft was in an unstable orientation. Although JAXA attemped recovery operations 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, JAXA officially announced.
Add WION as a Preferred Source
In recent years, Akatsuki has been the only active Venus orbiter. This means that humanity will have to wait for the next Venus-study mission to continue to learn about the planet.
What’s so special and mysterious about Venus ?
Venus is the second planet from the Sun and is a terrestrial planet that has a rocky, volcanic surface like earth and is almost as vast as Earth. However, its similarities with our home planet end there. Venus is the hottest planet in the solar system, and has an atmosphere densely packed with Carbon dioxide and corrosive clouds of suphuric acid. The pressure on the surface of Venus is 92 times as much as that on Earth’s surface, which means anything that isn’t built to withstand high pressure would be crushed on Venus. For perspective, the pressure on the surface of Venus is similar to the pressure experienced 1kilometer beneath Earth’s oceans.
Major discoveries by Akatsuki
Akatsuki was equipped with five cameras to photograph the Venusian atmosphere using infrared, visible light, and ultraviolet rays, and also uses other instruments to measure how temperature on the planet varies with altitude. AKATSUK had provided the world’s first data on how temperature varies between altitudes of 40 and 85 kilometers for the entire planet of Venus. Another discovery was on the great mystery regarding how the super rotation of Venus’ atmosphere was being maintained. On Venus, the upper atmosphere spins 60-times faster than the planet’s surface, a phenomenon known as super rotation. On Earth, the atmosphere spins at pretty much the planet’s speed. JAXA scientists and Japanese academia helped better humanity’s understanding of these mysteries.
When the Soviets landed their probes on Venus…
While the harsh environment of Venus is unthinkable for habitation, humanity has landed multiple robotic probes on Venus, all of them were carried out by the Soviet Union, during the 1980s. The Soviet Venera-series of Venus landers are the only ones to have ever landed on the planet. In fact, the Venera 7 was the first craft to land on another planet and transmit data back, while its successor missions sent bac surface photos from Venus, temperature data, audio of wind, chemical analysis of rocks, soil and more. SInce then, no lander has touched down on Venus, but there are future missions planned by NASA.
AloJapan.com