Jeu 23 Juil 2009 - 21:42
Russian Observatory TESIS Downloaded Images of the Solar Eclipse of July 22, 2009
Due to orbital location of the spacecraft, X-ray telescopes of the observatory were to see the eclipse twice. The first satellite crossed the eclipse zone at 4:30 Moscow time, thus becoming the first on our planet to see the shadow of the Moon still in space coming closer to the Earth. In 4 hours, when the people on the Earth couldn`t see the eclipse any more, the telescopes photographed the second deepest lunar path on the Sun.
The eclipse became an exam not only for the scientists who estimated mutual trajectories of the Sun, the Moon and the satellite to upload them, but for the spacecraft attitude system the basic elements of which are the solar sensors. Japan has lost its satellite Yohkoh, which had been functioning in orbit for more than 10 years, during the previous eclipse. Yohkoh attitude control system in sun-pointing mode rotated the spacecraft such that its solar arrays were not lit any more. Consequently, the accumulator batteries discharged, and the satellite was lost.
CORONAS-PHOTON was in more advantageous position during this eclipse. Even during the maximum phase, the Moon didn`t cover the Sun completely, leaving part of the solar disk still visible though as a thin sickle. The balance wheels rotated the satellite around the axis in an attempt to adapt to unusual brightness distribution on the Sun, but the satellite managed to remain in its operational state in these conditions.
Currently, TESIS is back in the nominal operational mode, and observes the full solar disk and its active zones. [Roscosmos]
Vous pouvez voir une série d'images ici http://www.tesis.lebedev.ru/info/tesis_20090722_eclipse_gallery_1.php
Et je vous conseille la belle vidéo ici http://www.tesis.lebedev.ru/info/movie/TESIS_eclipse_0030UT.wmv
ou celle-ci ici http://www.tesis.lebedev.ru/info/movie/TESIS_eclipse_0430UT.wmv
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