Launched in 1997, the Cassini probe entered orbit over Saturn in 2004, becoming its only man-made satellite. Saturn has been visited by three other spacecraft in the past, but none were designed to orbit the planet.
The Cassini-Huygens mission was designed to make use of sophisticated scientific instruments in order to study Saturn and its moons. While the Huygens probe landed on Saturn's largest moon Titan, the Cassini Orbiter was designed for long-term observation from orbit, making it the first and only artificial satellite above the planet. The orbiter was designed to study the structure of Saturn, as well as its complex system of rings.