Its sister craft, Pioneer 11, followed in April 1973. Initially designed as a backup, it soon established its own legacy. After a flyby of Jupiter in 1974, it used the planet’s gravity to slingshot toward Saturn. In September 1979, Pioneer 11 became the first spacecraft to encounter the ringed planet directly, discovering Saturn’s faint F ring, a previously unknown moon, and mapping the planet’s magnetic field.
Which forgotten probes explored the outer solar system before Voyager? The untold Pioneer story
