ESA scientists say the unprecedented flight profile is like that of "cosmic billiard ball."

Here is the mission schedule:

- February 26 2004: Liftoff from ESA's launchpad in Kourou, French Guiana.

- March 2005: A year after launch, Rosetta encounters the Earth, using the planet's gravity as a slingshot to boost speed.

- February 2007: Flies around Mars at a distance of just 200 kilometers (120 miles).

- November 2007: Second Earth flyby.

- November 2009: Third Earth flyby. Rosetta now at top speed, is catapulted through the asteroid belt, where it should be able to make some close observations of these primordial rocks.

- May 2011-January 2014: Hibernation. Systems are closed down to conserve fuel. During this period, Rosetta will be at its maximum distance from the Sun (about 800 million kilometers, 500 million miles) and from Earth (a billion kms, 600 million miles).

- January-May 2014: Rosetta awakes from its long slumber, fires thrusters to gradually brake its speed and near the comet.

- August 2014: Rosetta is inserted into an orbit of about 25 kilometersmiles) from the comet's nucleus. Uses cameras, radar, microwave, infrared and other sensors to scan comet's surface and sub-surface.

- November 2014: Rosetta sends down a robot laboratory, Philae. The lander is released at a height of about one kilometer (half a mile), touching down at walking speed. Fires a small harpoon to anchor itself, starts to send back pictures and conducts chemistry experiments on rock samples. Lander expected to function for at least a week.

- November 2014-2015: Comet Churyumov-Gerasimenko loops around the Sun, approaching to within 186 million kms (116 million miles) of the star, and then moves away from it, still escorted by Rosetta.

- December 2015: Scheduled end of mission. Both the comet and Rosetta head out of the inner Solar System. At this point, Rosetta will once again come close to Earth's orbit, more than 4,000 days after its odyssey began.

SPACE.WIRE