Selected in November 1993 as a cornerstone mission of ESA's long-term science programme, the Rosetta probe was launched by an Ariane 5 on 2 March 2004, on an 11-year journey to the Comet 67P/Churyumov-Gerasimenko.

Built by EADS Astrium, the Rosetta probe consists of a 3065-kg spacecraft (1578 kg dry mass) designed to enter orbit around the comet's nucleus in August 2014 after a series of gravity assist manoeuvres to gain enough orbital energy, with three swing-bys at Earth (March 2005, November 2007 and November 2009) and one at Mars (February 2007). En route to the comet, the probe will fly-by the asteroids (2867) Steins (September 2008) and (21) Lutetia (July 2010).

The spacecraft carries 11 science instruments to probe the comet's nucleus and map its surface in fine detail. It will also land a package of instruments (the Philae lander) to study some of the most primitive, unprocessed material in the Solar System. The mission will provide clues to the physical and chemical processes at work during the formation of planets, beginning 4600 million years ago.

Credits: ESA, image by AOES Medialab

Immediately after touchdown in November 2014, a harpoon will be fired to anchor the lander to the ground and prevent it escaping from the comet’s extremely weak gravity. The minimum targeted mission time for Philae is one week, but surface operations may continue for many months. The measurements from the Rosetta orbiter will last from August 2014 to the end of 2015.

Credits: ESA, image by AOES Medialab