The Satellite with Five Eyes
Images of Venus as it will look through Akatsuki's five onboard cameras. From the top: high sensitivity camera, long-wave infrared camera, ultraviolet imager, near-infrared surface camera, and near-infrared atmospheric camera. (C) JAXA.
The solar sail Ikaros. The sail part is stored inside the circular spacecraft, which has a diameter of 1.6 meters and stands 0.8 meters tall. When the craft is deployed into space, it spins around, causing the sail to unfurl. Each side of the sail is 14 meters in length. (C) JAXA.
One of Akatsuki's most highly developed senses is its "eyes." Akatsuki will be the first satellite of its kind to carry five different cameras. Two infrared cameras will pierce the thick cloud layer, carrying out observations of the surface and atmosphere of Venus, while a long-wave infrared camera will capture the infrared light that penetrates the clouds. With an ultraviolet imager that can pick up tiny changes in the clouds, high sensitivity cameras to pick up thunder, the Akatsuki will provide a full, rounded picture of what is happening where on Venus.
Akatsuki has been specially designed to give it an oval-shaped "elliptical" orbit. When it is at its furthest point from Venus, 8000km away, the satellite will carry out general observations of the planet as a whole. At its closest point, just 300km from the surface of the planet, it will study the details of the cloud layer in close-up. Akatsuki will orbit Venus every 30 hours, capturing images once every two hours and sending them back to Earth.
Scientists and researchers all over the world are paying close attention to Akatsuki's results. People have been arguing for more than twenty years about whether there is lightning on Venus, for example. The images sent back by Akatsuki should put an end to the debate once and for all. As well as what it has to tell us about the weather on Venus, the data provided by the Akatsuki mission should also help us predict what conditions might be like here on Earth if global warming continues.
The world's first solar-powered spacecraft, Ikaros, was also launched into space with Akatsuki. Described as a "space yacht," Ikaros is propelled by the power of the sun, rather than the wind. Tests on its performance will be conducted over a half-year period as it orbits Venus.
(Updated in July 2010)