Fig. 3

a Schematic view of orbital path of the Akatsuki orbiter around Venus and general observing plan during the ~ 10.5-day orbit. b A plan view of the orbits of Earth (outer ellipse), Venus (inner ellipse) and Akatsuki for orbit numbers 15, 16 and 17. An expanded view of three consecutive Akatsuki orbits around Venus is shown with the arrow pointing in the direction of the spacecraft in orbit. The dates and times indicate periapsis times. The dark shading in the circle represents the Venus nightside. Note that the size of Venus is exaggerated as compared to the size of the Akatsuki orbit for clarity. Similarly, in the upper panel the size of the Akatsuki orbit is also not to scale compared to the Earth and Venus orbits. The darker portion of the orbit indicates times when the orbiter is above the Venus equatorial plane. Sun avoidance zone for the high-gain antenna and the radiative cooler for the IR2 camera pose constraints on the pointing of the spacecraft when viewing Venus