The 2.2 billion-mile journey will take seven years and is the most ambitious voyage of space discovery ever attempted.
The joint US-European Cassini-Huygens mission had been delayed when technical problems and high winds halted the first launch attempt, on Monday.
But yesterday British scientists, who have contributed vital instruments and equipment for the mission, were celebrating at the Rutherford Appleton Laboratory in Didcot, Oxfordshire, as they watched the lift-off live on television.
Jeremy Curtis, a space design engineer at the laboratory, said after the launch, which took place at 9.43am: "There's great excitement and a lot of smiling faces here at the moment.
"It was a textbook launch. Everything seems to have gone exactly according to plan."Reuse content