Rosetta is named for the Rosetta Stone (right), an ancient script that provided the key to deconding Egyptian hieroglyphs.
Rosetta was initially going to visit another comet, but a launch delay caused it to miss its rendezvous window.
The team plans to fly past one asteroid during Rosetta's complex 10-year journey to the comet.
Rosetta gets its name from the famous Rosetta stone that led to the deciphering of Egyptian hieroglyphics almost 200 years ago.
The lander is named for Philae, an island in the river Nile on which an obelisk was found that gave historians the final clues to decipher the Rosetta stone.
Rosetta is the most detailed study of a comet planned to date.