Pioneer 11 became the first spacecraft to fly by Saturn, making its historic approach after launching in the early 1970s and utilizing a gravity assist from Jupiter to reach the ringed world.

During closest approach, the spacecraft passed roughly 2,100 kilometers above Saturn’s cloud tops and demonstrated the feasibility of traversing Saturn’s rings for the later Voyager missions.

After completing its Saturn encounter in October 1979, Pioneer 11 continued deep-space observations for 22 years, finally sending its last signal in late November 1995 from about 4 billion miles from Earth.

NASA’s Pioneer 11 plaque, designed by prominent scientists, foreshadowed the golden record concept later used on the Voyager probes; a replica is now displayed at the Smithsonian National Air and Space Museum.

The mission was conceived as a twin of Pioneer 10 to test survival through the asteroid belt and Jupiter’s radiation, setting the stage for the Voyager outer-planet tour during the rare late-1970s planetary alignment.

Pioneer 11 identified several Saturnian moons, detected a new ring, provided the first evidence of Saturn’s magnetic field, and captured Titan in imagery along with hundreds of Saturn photos.