Voyager 2
File:Voyager.jpg
Voyager 2 – 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.

Image and info source: (CreationWiki –
http://creationwiki.org/Voyager_2public domain)