The launch that took place the 2nd of March 2004 on an ARIANE-5 launcher, will lead to make the rendez-vous with the comet mid-2014 and the end of the mission, in December 2015, after the comet perihelion.

To meet its target, the ROSETTA probe will need a trajectory requesting four gravity assists (Earth, Mars, Earth, Earth) allowing to modify its initial trajectory without undue consumption of ergols.

This strategy thus enforces a long duration cruise (10 years) which will be used to fly-by asteroids. During the remaining time, for reliability reasons as well as operationnal costs decrease, the probe will be in Cruise mode, with a minimal exchange of information with the Earth. This strategy has already been used with the GIOTTO probe.

When the probe is very far from the sun in 2012 and 2013, it is put in Hibernation mode, without any communication link with the Earth.
Beginning of 2014, the probe is approaching the comet and is waked up to perform several brakings that will place it in July 2014 in orbit around Churyumov-Gerasimenko. A first global mapping of the surface allows to locate the most interesting landing sites. In September the orbit is lowered to achieve a close observation of these sites. On 20 November 2014 the Orbiter carries the Lander at its separation location.
30 minutes later Philae has landed on the comet and starts its nominal 5 days scientific studies.
It is hoped that the Lander will go on its mission beyond these 5 days depending on power that solar panels recovering it will provide at this large distance from the sun.