"Hello", so we heard from a lost comet lander now awaken!

"Hello", so we heard from a lost comet lander now awaken!

Many months ago, a small space probe named Philae skipped across the surface of Comet 67P/Churyumov-Gerasimenko when the lander's harpoon-like anchoring mechanism failed. It came to rest in a shady spot and, without enough sunlight to keep it powered, it fell asleep after about 60 hours of operation.

However, months after Philae nodded off, lander system engineer Laurence O'Rourke told CNN that Philae needed almost 6 watts of power to reboot itself, 9 watts to accept communications and 19 watts to allow two-way communication with the orbiter -- not a great deal of power when you consider energy-saving lightbulbs use 20 watts or fewer.

There was speculation in March that Philae could be awake but lacking the necessary power to communicate with Rosetta, which was in orbit around Comet 67P looking for the washing machine-sized lander.

Scientists sent "blind commands" in hopes that the lander could process the instructions even if it couldn't respond, O'Rourke told CNN in March. But there was not immense confidence that Philae could be revived.

Asked his thoughts Sunday, O'Rourke told CNN he was "thrilled" contact was re-established, which "allows us to do more science."

"We are all delighted -- delighted that Philae survived the long winter. It's a great opportunity," he said.

When the lander snapped its hibernation spell Saturday, it "spoke" with the scientists on the ground for 85 seconds, ESA said.

"We have also received historical data -- so far, however, the lander had not been able to contact us earlier," Ulamec said, explaining that Philae must have been awake before Saturday night.