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European comet-chasing satellite awakens from hibernation

The Rosetta satellite even tweeted as Gaeilge.

Image: ESA

THE EUROPEAN SPACE Agency has heard from one of its satellites for the first time in 31 months.

The satellite Rosetta is chasing Comet 67P/Churyumov-Gerasimenko. Once it catches up with 67P, Rosetta will attempt to become the first satellite to land on a comet.

To do so, it will slow down to about 24,600 miles per hour to match the comet’s speed. It will then land on the fast-moving rock and carry out experiments as it orbits the sun.

Operating on solar energy alone, Rosetta was placed into a deep space slumber in June 2011 as it cruised out to a distance of nearly 800 million km from the warmth of the sun, close to the orbit of Jupiter.

Now, as Rosetta’s orbit has brought it back to within only 673 million km from the sun, there is enough solar energy to power the spacecraft fully again.

Thus today, still about nine million km from the comet, Rosetta’s pre-programmed internal ‘alarm clock’ woke up the spacecraft. After warming up its key navigation instruments, coming out of a stabilising spin, and aiming its main radio antenna at Earth, Rosetta sent a signal to let mission operators know it had survived the most distant part of its journey.

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The signal was received by NASA’s Goldstone ground station in California at 6:18pm GMT, during the first window of opportunity the spacecraft had to communicate with Earth. The signal was confirmed by the Twitter account for the mission, which even tweeted in Irish.

“We have our comet-chaser back,” says Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.

“With Rosetta, we will take comet exploration to a new level. This incredible mission continues our history of ‘firsts’ at comets, building on the technological and scientific achievements of our first deep space mission Giotto, which returned the first close-up images of a comet nucleus as it flew past Halley in 1986.”

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