A spacecraft launched in 2004 hibernated for 3 years, Wake's up Today.
Wake up Rosetta! Landmark mission to take comet-chasing spacecraft out of three-year hibernation begins
1. Rosetta spacecraft aims to better understand the composition of comets
2. It launched in 2004 and has since travelled around the sun five times
3. Probe has been hibernating for most of the past three years to save power
4. The spacecraft's alarm sounded at 10am this morning, but it is expected to take seven hours for it to power up and send a signal back to Earth
5. The probe will land on comet 67P/Churyumov–Gerasimenko in November
6. Scientists hope the mission will provide more clues about how the solar system came into existence.
A much-anticipated alarm has sounded to wake up the Rosetta probe from its deep space slumber.
The comet-chasing spacecraft was due to wake from an almost three-year hibernation at 10am this morning (5am EST) and phone home to say all is well.
But astronomers are in for a nail-biting wait as the spacecraft's systems will take several hours to power up and the signal has to travel more than 500 million miles (800 million km) back to Earth.Rosetta was launched in 2004 and has since travelled around the sun five times, picking up energy from Earth and Mars to line it up with Comet 67P. This infographic shows Rosetta's journey. Prior to the wake up call, the probe carried out a series of orbits to slingshot itself towards its target
The probe will rendezvous with comet 67P/Churyumov-Gerasimenko in the coming months and drop a space lander onto its icy surface in November.
Ground control teams hope to have confirmation of Rosetta's resuscitation by 6.30pm (1:30pm EST), the space agency said.
'We don't know the status of the spacecraft,' said Paolo Ferri, head of mission operations at ESA.
'There is a possibility that we're not going to hear anything.
'We've taken all possible precautions for this not to happen but of course we cannot exclude that problems may have happened.'Employees work in the control room of ESA in Darmstadt, Germany. Because the spacecraft's systems will take hours to power up and the signal has to travel more than 500 million miles (800 million km) back to Earth, scientists will not see the first sign of before early evening
A scientist is pictured here with an airworthy copy of space probe Rosetta. Manoeuvres designed for the actual space probe are simulated with the replica
The spacecraft, which carries a 220lb (100 kg) lander called Philae, has been hibernating for most of the past three years to save power.
It is due to reach a 2.4-mile (4 km) diameter comet called 67P/Churyumov-Gerasimenko in August.
Unlike previous comet probes, Rosetta won't just sail by. The spacecraft is designed to put itself into orbit around 67P for more than a year of close-up studies.
Comets are believed to be the pristine leftover remains from the formation of the solar system some 4.6 billion years ago.This is the image that scientists are waiting to see. The spike in the middle will tell ESA if Rosetta is awake. This screenshot is from an earlier simulation and is expected to be seen later today when Rosetta sends its radio signal 807 million km across our solar system to Earth
Scientists hope the mission will provide more clues about how the solar system came into existence, much like the Rosetta Stone - after which the spacecraft is named - provided a blueprint for deciphering ancient Egyptian hieroglyphs.
‘Rosetta should become a key element for our understanding of the history of the solar system,’ Stephan Ulamec, a Rosetta project manager, said in an interview with Reuters last month.
Scientists believe the spacecraft’s startrackers are now beginning to warm up, taking around six hours.
Its thrusters will fire to stop the slow rotation. A slight adjustment will be made to Rosetta’s orientation to ensure that the solar arrays are still facing directly towards the sun, before the star trackers are switched on to determine the spacecraft’s attitude.
Once that has been established, Rosetta will turn directly towards Earth, switch on its transmitter and point its high-gain antenna to send its signal to announce that it is awake.
Because of Rosetta’s vast distance, it will take 45 minutes for the signal to reach the ground stations.
Deep space tracking dishes will be listening out for the signal, starting with Nasa’s 70 m-diameter station at Goldstone, California, followed by, as the Earth rotates, the Canberra station in eastern Australia.For the coldest, loneliest leg of the mission, as Rosetta travelled out towards the orbit of Jupiter, the spacecraft was put into deep-space hibernation
Scientists believe the spacecraft's star trackers are now beginning to warm up, taking around six hours. Its thrusters will fire to stop the slow rotation. A slight adjustment will be made to Rosetta's orientation to ensure that the solar arrays are still facing directly towards the sun