image of Planet-C

6. Concluding remarks

The Japan Aerospace Exploration Agency is planning the Venus Climate Orbiter/PLANET-C mission aiming at understanding the atmospheric circulation of Venus, with additional targets being the exploration of the ground surface and the zodiacal light observation. This paper describes the science objectives and instrument specifications as well as the characteristics of the spacecraft design. The instruments, the spacecraft design and the orbit of VCO are optimized for imaging observations of meteorological phenomena. The onboard instruments are cameras to map clouds and minor constituents with large-format array detectors (IR1, IR2, UVI, LIR), a high-speed imager (LAC), and USO for radio science. In the nominal sequence, all cameras except LAC will be operated every 2 hours to get global views of the Venusian atmosphere, and LAC will be operated in the shadow region of Venus. Such systematic, continuous imaging observations will provide us with an unprecedented large dataset of Venusian meteorology.

The science plan of VCO is complementary with that of the ESA’s Venus Express. The striking difference between VCO and Venus Express is that the former focuses on global imaging from equatorial orbit, while the latter puts emphasis on spectroscopy from polar orbit, although Venus Express also has imaging capabilities. The cooperation in the data analysis between the VCO team and the Venus Express team should also be fruitful; analyzing both VCO and Venus Express data sets with a common algorithm, and analyzing each data set with different algorithms developed independently by the two teams, would be helpful to ensure the reliability of the results.