Which spacecraft was the first to orbit Saturn?

Cassini was the first spacecraft to orbit Saturn. The Cassini orbiter entered Saturn orbit on July 1, 2004, after a nearly seven-year journey through the Solar System, beginning the first mission to study the planet and its system from orbit.

The spacecraft was part of the Cassini–Huygens mission, a partnership involving NASA, the European Space Agency, and the Italian Space Agency. Cassini carried the Huygens probe, which separated from the orbiter and descended through the atmosphere of Saturn’s moon Titan in January 2005, becoming the first spacecraft to land in the outer Solar System.

Several earlier spacecraft visited Saturn, but none entered orbit. Pioneer 11 made the first close flyby in 1979, followed by Voyager 1 in 1980 and Voyager 2 in 1981. New Horizons also observed Saturn’s system from a distance, but it was traveling onward to Pluto. Cassini remained active for more than 13 years before deliberately plunging into Saturn’s atmosphere on September 15, 2017.