RPIF
pagePioneer 10 and 11 were designed to conduct a flyby of Jupiter and continue indefinitely into deep space. Pioneer 10 was the first man-made object to leave the solar system. Pioneer 11 went on to fly by Saturn as well.
Voyager 1 and 2 were identical spacecraft designed to investigate Jupiter, Saturn, Uranus and Neptune and their moons. They successfully returned tens of thousands of images. Voyager 1 was launched September 5, 1977, Voyager 2 on August 20, 1977. Voyager 1 passed Jupiter in March 1979, Saturn in November 1980, and followed a trajectory out of our Solar System. Voyager 2 passed Jupiter in July 1979, Saturn in August of 1981, Uranus in January 1986, and Neptune in August 1989 before it too left the Solar System. Pluto was not explored because its orbital position was out of range of the spacecraft's path. The Voyager spacecraft were launched to take advantage of the alignment of the planets that made their "grand tour" possible. Such alignment of the planets will not occur again until 2157. (V2 still relaying deep space data.)
For more information on Voyager see: Exploring The Planets - Voyager
RPIF Jupiter - RPIF Saturn - RPIF Uranus - RPIF Neptune
10/15/99