Launch Date May 21, 2010
Launch Site Tanegashima Space Center, Tanegashima, Japan
Destination Venus
Type Orbiter
Status Successful–In Progress
Nation Japan
Alternate Names 2010-020D, Planet-C, Venus Climate Orbiter, 36576


Study weather patterns on Venus, confirm the presence of lightning in thick clouds and search for signs of active volcanism.


Recovered from missed orbit insertion in 2010 and entered Venus orbit in 2015. Akatsuki is Japan's first successful mission to explore another planet.

Key Dates

May 21, 2010: Launch

Dec. 6, 2010: Venus Orbit Insertion - 1st Attempt

Dec. 7, 2015: Successful Venus Orbit Insertion

In Depth

The Venus Climate Orbiter mission (PLANET-C), or "AKATSUKI", is studying the atmospheric circulation of Venus. Meteorological information will be obtained by globally mapping clouds and minor constituents successively with four cameras at ultraviolet and infrared wavelengths, detecting lightning with a high-speed imager, and observing the vertical structure of the atmosphere with radio science techniques.

The equatorial elongated orbit with westward revolution matches the Venusian atmosphere, which rotates westward. The systematic, continuous imaging observations will provide us with an unprecedented large dataset of the Venusian atmospheric dynamics. Additional targets of the mission are the exploration of the ground surface and the observation of zodiacal light. The mission complements the European Space Agency's (ESA) Venus Express, which orbited Venus until 2014.


Launch Vehicle: H-2A

Spacecraft Mass: 320 kilograms

Additional Resources

National Space Science Data Center Master Catalog: Akatsuki

Institute of Space and Astronautical Science: Akatsuki

ISAS Planet-C Project Site

Japan Aerospace Exploration Agency

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