It’s being called “the most important alarm clock in the solar system” — tomorrow, Monday January 20, at 10:00 GMT (which is 5:00 a.m. for U.S. East Coasters like me) the wake-up call will ring for ESA’s Rosetta spacecraft, bringing it out of hibernation after over two and a half years in preparation of its long-awaited rendezvous with a comet later this year.
The signal will incite the warming of Rosetta’s star trackers, which allow it to determine its orientation in space. Six hours later its thrusters will fire to stop its slow rotation and ensure that its solar arrays are receiving the right amount of sunlight. Using its thawed-out star trackers Rosetta will aim its transmitter towards Earth and, from 500 million miles (807 million km) away, will send a thumbs-up message that everything is OK and it’s time to get to work.
From that distance the transmission will take 45 minutes to reach us. Rosetta’s first signal is expected between 17:30 – 18:30 GMT (12:30 – 1:30 p.m. ET).
And, if all is well, Rosetta has a very exciting year ahead! Read the rest of this article here.
UPDATE Jan. 20: Rosetta has awoken! This afternoon at 18:18 UTC, after 48 minutes of increasingly tense anticipation, a signal was received from the spacecraft by both NASA’s Deep Space Network in Goldstone, CA and the ground station in Canberra, Australia. Rosetta is up and running and so far seems to be in good condition — Go Rosetta and Philae! Read the full story from ESA here.