Cassini-Huygens spacecraft. European Space Agency's (ESA) Huygens probe attached to the Cassini orbiter. The Cassini-Huygens mission was launched from Earth in 1997 and took 7 years to reach Saturn and its moons. The Huygens probe separated from Cassini on 25th December 2004, and descended to the surface of Saturn's largest moon, Titan, in early 2005. The Cassini orbiter then continued on to Saturn itself.