An H-2A rocket successfully blasted Japan's new planetary probe Akatsuki (daybreak) into orbit early May 21. Also sent into orbit were four small satellites developed by university students and the "space yacht" Ikaros, which will be propelled by sunlight.
Akatsuki, developed by the Japan Aerospace Exploration Agency, is expected to travel some 520 million km and reach Venus' orbit in December. While in oval orbit 300 km to 80,000 km from Venus for more than two years, it will observe the carbon dioxide atmosphere, analyze the constituents and movements of sulfuric acid clouds, and determine how storm winds of up to 360 kph are generated. It will use five observation instruments including ones that catch near-infrared and ultraviolet rays from Venus.
The ¥25.2 billion Akatsuki represents Japan's first planetary exploration mission since the Nozomi (hope) probe, which was launched in 1998 but failed to go into a Mars orbit in 2003 as planned. Akatsuki may offer some hints as to why Venus and Earth, which are similar, came to have different environments.