Cassini-Huygens

Launched in October 1997 by NASA and ESA, the Cassini-Huygens spacecraft arrived at Saturn in July 2004 and spent 13 years orbiting the ringed giant. The mission discovered active geysers of water ice on Enceladus suggesting a subsurface ocean that could harbour life, landed the Huygens probe on Titan in 2005 to reveal rivers of liquid methane, and ended with a deliberate death dive into Saturn's atmosphere on 15 September 2017 to protect those ocean worlds from contamination.