European Space Agency is preparing to wake up its most ambitious space craft ahead of a mission to land on a comet.

The Rosetta space craft was launched in 2004 to track and chase after a comet, and has spent more than two years in 'hibernation' to conserve power.

Now the space agency has set an alarm - literally - for 10 am on Monday, and hopes that the craft will activate on time.

If successful, the probe will send an "I'm awake" message back to Earth and start the process of travelling to its rendezvous point with the Comet 67P/Churyumov-Gerasimenko.

If all goes well, Rosetta will collect data about the 4km-wide comet from August until October, and then try to drop a small robot onto its surface.

Rosetta is currently located about 673 million km from the Sun, but has already made five round trips around our star in order to pick up the energy needed to line up with its final destination.

On its blog ESA has lots of details about exactly what it's hoping to hear from Rosetta, as well as the schedule for today's events (hopefully), and tools to work out how far from the Sun it really is.

Here's the rough schedule:

  • 9:15am: ESA live-broadcast starts
  • 10am: ESA sends its wake-up call to Rosetta
  • 10:45am: Rosetta receives call
  • 4pm: Rosetta fires thrusters to stop slow-rotation
  • 4pm: Rosetta checks solar arrays to ensure power supply
  • 4.45pm: Rosetta sends 'I'm awake message back to Earth'
  • 5:30pm: Earth receives Rosetta's message

ESA is also broadcasting the wake-up call live:

Watch live streaming video from eurospaceagency at livestream.com
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  • Undated artistic sketch of Rosetta, the one billion-euro comet chasing space probe due to be launched in January 2003, whom the mission has been abandoned and a new mission will be found later, the European Space Agency (ESA) said 15 January 2003. Five or six other possible comets will be studied before a new target is selected, a decision likely not to be taken before the year's end. (Photo credit should read J.HUART/AFP/Getty Images)

  • This handout picture from the European Space Agency (ESA) retrieved on September 3, 2008 shows an artist's rendition of ESA's probe Rosetta.

  • Artist's impression of the European Space Agency (ESA) probe Rosetta with Mars in the background.

  • This handout image provided by the European Space Agency, transmitted by the space craft Rosetta, shows the asteroid Lutetia at closest approach July 10, 2010 between Mars and Jupiter in outer space.

  • This handout image provided by the European Space Agency, transmitted by the space craft Rosetta, shows a close-up view of a possible landslide and boulders at the highest resolution on the asteroid Lutetia July 10, 2010 between Mars and Jupiter in outer space.

  • This undated image provided by the European Space Agency ESA shows an artist's impression of the Philae lander

  • In this Dec. 10, 2013 file picture a European Space Agency, ESA, employee sits in the control room for the Rosetta mission at the ESA in Darmstadt, Germany.

  • This image provided by the European Space Agency ESA shows an artist’s impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko

  • In this 2013 file photo provided by the European Space Agency, ESA, employees work in the control room of ESA in Darmstadt, Germany.