Venus Express was originally set to be launched on 26 October by a Russian rocket, but it was postponed after pre-launch tests revealed problems with the rocket.
The European space probe carries a set of instruments to study the atmosphere of Venus and scientists hope the mission will help provide clues about the features and the evolution of the planet.
The European Space Agency says it has invested 220 million euros ($265 million) in the mission.
(AFP/AP)