The European Space Agency (ESA) announced in the early hours of Saturday that its Philae probe had entered "idle mode," but only after successfully sending its data home from a deep-space comet.
Part of the ESA's Rosetta mission, the Philae lander touched down on comet 67P/Churyumov-Gerasimenko this week, but did not land precisely where planned. As a result of it settling in a shadowy position, perhaps by a cliff wall or inside a crater, the probe's solar battery life had become a major concern for the unprecedented mission.
"Prior to falling silent, the lander was able to transmit all science data gathered during the First Science Sequence," said lander manager Stephan Ulamec from Germany's national aeronautics and space research center (DLR), which operated the probe. "This machine performed magnificently under tough conditions, and we can be fully proud of the incredible scientific success Philae has delivered."
ESA still hoping for more
As the Philae probe transmitted data more than 500 million kilometers (300 million miles) back to Earth, the ESA posted repeated updates on Twitter in the probe's name, charmingly reporting in the first person from comet 67P. "Philae" twice made reference to its dwindling battery life and enforced hibernation.
According to the ESA Rosetta mission's blog post, issued shortly after contact was lost at 01:36 a.m CET (00:36 GMT/UTC), this "nap" might not be permanent, with a little luck.
Another of Philae's last actions on Friday was to rotate the lander's main body, to which the solar panels are fixed. As a result, the Rosetta mission said this boosted the chance of Philae coming back online, as it "may have exposed more panel area to sunlight." The public voice of the probe on Twitter also alluded to this possible reawakening, with the first possible window due later on November 15.
The ESA's Rosetta spacecraft is tracking comet 67P's path towards the sun; it is the first ever to successfully rendezvous with and orbit a comet. The makeup of comets is broadly believed to have remained almost unchanged since the formations of our solar system some 4.6 billion years ago; it is hoped that the findings could improve our understanding of how the planets and life evolved.
msh/jm (AFP, AP, Reuters)