– the voyager space craft were launched by NASA in 1977 originally to visit
the gas giant planets Jupiter and Saturn. A highly favorable trajectory that
resulted from its flyby of Saturn convinced mission controllers to extend the
mission to visit Uranus and Neptune as well. The surprising discoveries that
this vessel made, and especially its rendezvous with four gas giants, make it
the most productive rocket probe ever launched.
info source: (CreationWiki –