NASA’s Pioneer 11 carried the first spacecraft to fly past Saturn’s moon Titan.
Pioneer 11 launched on April 5, 1973, and used Jupiter’s gravity to alter its path toward Saturn. It reached Saturn on September 1, 1979, becoming the first spacecraft to encounter the planet closely. During the mission, it also passed Titan at a distance of about 21,000 kilometers.
The spacecraft studied Saturn’s rings, atmosphere, magnetic field, and radiation environment. Its close approach helped mission planners assess hazards for later missions. Pioneer 11’s observations contributed to the decision to send Voyager 1 on a trajectory that would make a close Titan encounter.
Cassini later spent years orbiting Saturn and Huygens landed on Titan in 2005, but that mission came decades afterward. Pioneer 10 visited Jupiter, not Saturn, and never made the first Titan flyby.