BERLIN (TheBlaze/AP) — It took more than 10 years for a probe to reach its comet target in space. But when it finally did and successfully touched down, it quickly became clear to scientists that its mission was in jeopardy. The Philae spacecraft landed in an area where there was not enough light to power its solar system.
But to scientists' relief and delight, Philae woke up and communicated with Earth over the weekend after seven long months of silence, the European Space Agency announced Sunday. Though the probe is getting adequate sunlight to recharge now, it will likely go dormant again in the fall — possibly forever.
The combination photo of different images taken with the CIVA camera system released by the European Space Agency ESA on Thursday Nov. 13, 2014 shows Rosetta�s lander Philae as it is safely on the surface of Comet 67P/Churyumov-Gerasimenko, as these first CIVA images confirm. One of the lander�s three feet can be seen in the foreground. hilae became the first spacecraft to land on a comet when it touched down Wednesday on the comet, 67P/Churyumov-Gerasimenko. (AP/Esa/Rosetta/Philae)
Philae became the first spacecraft to settle on a comet when it touched down on icy 67P/Churyumov-Gerasimenko in November. But the solar-powered probe came down with a bounce and ended up in the shadow of a cliff instead of in direct sunlight.
As a result, Philae managed to conduct experiments and send data to Earth for only about 60 hours before its batteries ran out and it was forced to shut down its systems and go silent.
Scientists had hoped the probe would wake up again as the comet approached the sun, enabling Philae's solar panels to soak up enough light to charge the craft's main battery. But there were fears its mission would be cut short.
Those fears were dismissed at 10:28 p.m. (2028 GMT; 4:28 p.m. EDT) on Saturday, when the lander sent a signal back to Earth.
"I'm not really surprised it happened, but if you wait for several months and then suddenly in the middle of the night you get a call saying, 'We have a signal from Philae,' it's exciting," said Stephan Ulamec, project manager at the German Aerospace Center, or DLR. "We're very happy."
The picture released by the European Space Agency ESA on Wednesday, Nov. 12, 2014 was taken by Rosetta's lander Philae shortly after its separation with the lander’s CIVA-P imaging system and captures one of Rosetta's 14 metre-long solar wings. On Wednesday, Nov. 12, 2014 the Philae lander detached from Rosetta and started it's descent to the 4-kilometer-wide (2.5-mile-wide) 67P/Churyumov-Gerasimenko comet. (AP Photo/ESA)
The brief burst of communication contained 300 packages of data that were relayed by the probe's mother ship, Rosetta, which is orbiting the comet.
"We only received data for about 85 seconds. These data are housekeeping and system data from the lander," Ulamec said. But it was enough to tell scientists that the probe is doing well and getting sufficient sunlight to keep communicating.
Ulamec said the probe appears to have been awake for several days before it called home.
NPR's Geoff Brumfield called the lander coming back online "really a minor miracle."
Scientists will now work to change Rosetta's orbit so that the link to the lander lasts longer and they can start sending commands for it to carry out new measurements. The next opportunity to communicate with Philae should come on Sunday night, Ulamec said.
Scientists also hope that Philae's restart will allow them to pinpoint where on the 2.5-mile (4-kilometer)-wide comet the washing machine-size probe landed. Its exact location has been a mystery.
On Aug. 13, the comet will reach the point at which it is closest to the sun before swinging back out again. Ulamec said the lander should get enough sunlight to operate until October, when it will once again fall silent, possibly forever.
Front page image via the European Space Agency.