Like a groggy traveler after a long, cold night, the European Space Agency's comet-chasing Rosetta spacecraft woke up, warmed up and called home Monday before setting off on the final leg of its journey.
Rosetta shook off 31 months of sleep, during which it traveled into the dark reaches of the solar system, and contacted its operators Monday evening. Cheers erupted in the ESA mission control center in Darmstadt, Germany, when a signal from Rosetta arrived shortly after 7 p.m. (1 p.m. ET).
"The spacecraft is there, it's awake, and I think we are all overwhelmed," mission manager Gerhard Schwehm told reporters. Now, he said, controllers will have "two busy years ahead of them" as it approaches its target, Comet 67P/Churyumov-Gerasimenko, and follows it around the sun.
There was only an hour window for the signal to reach Earth, putting scientists on pins and needles.
"The spacecraft decided to make us suffer after two and half year," Paolo Ferri, head of ESA Mission Operations told CNN. "We came almost to the end of the window, we were very tense," he said.
The unmanned probe was launched in 2004 and is now nearly 500 million miles (800 million kilometers) from the Sun - a distance that puts it just past the orbit of Jupiter. At that distance, the message it beamed back took 45 minutes to arrive.