IKAROS took this photo on December 8, 2010, documenting its flight past Venus.
If I understand the translation of this IKAROS Tweet correctly, it took two weeks from the time the photo was taken to transmit the image successfully to Earth -- IKAROS' transmitter is not very powerful, and its opportunities to communicate are increasingly rare as the distance between the spacecraft and Earth increases. That also explains the tiny size of the image -- only thumbnail versions could be transmitted at the available data rate.
Here's the full text of the press release in English:
The Small Solar Power Sail Demonstrator "IKAROS" has been in its regular operation phase for about six months to verify navigation by the world's first solar sail device and power generation by the thin-film solar battery. As its missions have been achieved, the IKAROS has completed its regular operations. The demonstrator will be in the post operational phase, which leads to the development of a successor while acquiring basic knowledge of solar power sail technology including a navigation guidance technique.
On the Japanese side of the website there is a PDF report containing much more detail. Without spending the time to run every bit of text from the PDF through Google Translate, I don't know the full extent of what's discussed in the report, but it does appear that when JAXA talks about completion of regular operations, they do not mean that the IKAROS mission is over. There are trajectory diagrams showing where the spacecraft will be through December 2012. So I think that what they are saying is that IKAROS' primary mission is complete, and that the PDF report discusses the achievement of the missions' goals: the demonstration of several new technologies, including deep-space sail deployment, thin-film solar cells, and control of the sail by liquid crystal technology, among others.
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