ESA's comet-chasing Rosetta probe wakes up after 31-month deep sp

Updated January 21, 2014 12:45:07 The comet-chasing probe Rosetta has woken up and is operational after a 31-month hibernation, according to the European Space Agency (ESA).The ESA sent out a tweet confirming Rosetta's awakening, mimicking the signal sent back from deep space by the probe.