On April 6, 1973, Pioneer 11 was launched from Cape Canaveral. The 2.9-meter long unmanned spacecraft was the second mission (after its sister probe Pioneer 10) to investigate Jupiter and the outer solar system, and the first to explore the planet Saturn and its main rings. The spacecraft made a success to Saturn flyby and then followed an escape trajectory from the solar system.

Also called Pioneer G, Pioneer 11’s objectives were to study the interplanetary and planetary magnetic fields; solar wind properties; cosmic rays; transition region of the heliosphere; neutral hydrogen abundance; distribution, size, mass, flux, and velocity of dust particles; Jovian aurorae; Jovian radio waves; the atmospheres of planets and satellites; and the surfaces of Jupiter, Saturn, and some of their satellites. Pioneer 11 was developed out of NASA Ames Research Center as part of the Pioneer series of spacecraft.