Which spacecraft made the first close-up study of Saturn and its rings?

NASA’s Pioneer 11 made the first close-up study of Saturn and its rings when it flew past the planet on September 1, 1979.

Pioneer 11 launched in 1973 and first traveled through the asteroid belt before using Jupiter’s gravity to alter its path toward Saturn. During its Saturn encounter, it passed about 21,000 kilometres above the planet’s cloud tops. Its instruments measured Saturn’s magnetic field, radiation environment, temperature, and atmosphere, while cameras returned images of the planet and rings.

The flyby was also a valuable reconnaissance mission. Engineers needed information about ring particles and the Saturnian environment before sending the Voyager spacecraft through the system. Pioneer 11 discovered a previously unknown narrow ring and helped identify the outer A ring structure.

Cassini later performed the most extensive study of Saturn, entering orbit in 2004. However, Cassini was not first: Pioneer 11 achieved the initial close encounter in 1979.