In December 2010, the Japanese climatic spacecraft for studying Venus “AKATSUKI” (also known as Planet-C), after five and a half months in space, could not enter the orbit of Venus due to problems with the steering nozzle. AKATSUKI actually entered circumsolar orbit after it failed to enter a cloud-covered planet orbit and planned past it. Immediately after this, the JAXA mission engineers were able to figure out the cause of the problem and developed a workaround for re-entering the orbit.
Now, five years later, the last chance will be presented on Monday, December 7th.
In case of success, AKATSUKI will collect information on the atmosphere of Venus during its elliptical coil from eight to nine days long. Initially, the duration of this mission was planned for Venus for at least two years, so the duration will depend on the viability of the spacecraft's batteries.
Venus crescent image captured by AKATSUKI two days after passing past Venus in December 2010
After several ignitions of the AKATSUKI orbital shunting engine (OME), it turned out that this engine can no longer fulfill its purpose, however, the reactor control system (RCS) of the steering device can deliver the spacecraft to the orbit of Venus - especially now that it is slightly lighter after a reset waste fuel for OME.
According to the JAXA website, the AKATSUKI device is currently in good condition, and completed several orbital maneuvers to complete the attempt on December 7th. Confirmation of entry into orbit will be known a few days later.
Now that the Venusian ESA Express has completed its mission and disappeared, plunging into the dense atmosphere of the planet, AKATSUKI may soon become our only spacecraft in orbit of Venus.