The European Space Agency’s Rosetta spacecraft has successfully woken up after almost three years in hibernation.
The craft at the heart of ESA’s €1-billion (US$1.4-billion) comet-hunting mission was shut down in 2011 to save energy while travelling in deep space (see ‘Comet craft ready to wake’). Rosetta successfully re-established communications with Earth on 20 January.
With an alarm pre-set for 10:00 GMT, a signal was expected at any time from 17:30 GMT, once the spacecraft had warmed up and turned its antenna towards Earth. But Rosetta kept everyone guessing, with the first sign that everything had gone to plan only arriving around 40 minutes later.
ESA’s European Space Operations Centre erupted in cheering and hugging as small spikes appeared in radio signals received at NASA deep-space communications centres in Canberra and in Goldstone, California.
Messages take 45 minutes to travel the 807 million kilometres each way to the craft. This means ESA scientists will have to wait another 90 minutes after the first signal before receiving a health report from Rosetta.
All being well, the craft will now journey to its target, the comet Churyumov-Gerasimenko, which it will approach in August. Rosetta will observe the comet up close before landing a probe in November. This will be the first time a soft landing has even been attempted on a comet.
In the ESA control room, spacecraft-operations manager Andrea Accomazzo was delighted to see Rosetta come back to life. “I think it’s been the longest hour of my life,” he said.