A spacecraft to Saturn launched in 1997 October, jointly built by NASA, ESA, and the Italian Space Agency. It consisted of two parts: the Cassini orbiter, and the Huygens lander to study Saturn's largest satellite, Titan. Cassini–Huygens went into orbit around Saturn in 2004 July, having undergone two gravity-assist flybys of Venus and one each of the Earth and Jupiter en route; it made observations of Jupiter during its encounter in 2000 December. Huygens landed on Titan in 2005 January, measuring atmospheric conditions during its descent and transmitting from the surface for over an hour. The Cassini orbiter is studying Saturn's atmosphere, satellites, and rings.
http://saturn.jpl.nasa.gov/home/index.cfm Official mission website.
http://www.esa.int/SPECIALS/Cassini-Huygens/index.html ESA mission website.
Subjects: Astronomy and Astrophysics.