Voyager 1 flew past Saturn and photographed the moon Pandora in 1980.
NASA’s Voyager 1 reached the Saturn system in November 1980 after launching from Earth in 1977. During the encounter, its cameras studied Saturn, the rings, and numerous moons. Those observations led to the discovery of Pandora, which was initially assigned the provisional designation S/1980 S 26.
Pandora is a small irregular satellite near Saturn’s F Ring. It is one of two shepherd moons associated with that ring, the other being Prometheus. Their gravitational interactions help shape and confine ring material, although modern observations show the F Ring to be highly dynamic.
Voyager 2 also visited Saturn, but it arrived in 1981 and was not the spacecraft credited with Pandora’s discovery. Cassini later made much closer and more detailed studies of Saturn’s moons and rings from orbit. That later mission is therefore a common but incorrect answer to the discovery question.