Voyager 1 was one of a pair of spacecraft launched to explore the planets of the outer solar system and the interplanetary environment. Each Voyager had as its major objectives at each planet to: (1) ... investigate the circulation, dynamics, structure, and composition of the planet's atmosphere; (2) characterize the morphology, geology, and physical state of the satellites of the planet; (3) provide improved values for the mass, size, and shape of the planet, its satellites, and any rings; and, (4) determine the magnetic field structure and characterize the composition and distribution of energetic trapped particles and plasma therein.
Originally planned as a Grand Tour of the outer planets, including dual launches to Jupiter, Saturn, and Pluto in 1976-77 and dual launches to Jupiter, Uranus, and Neptune in 1979, budgetary constraints caused a dramatic rescoping of the project to two spacecraft, each of which would go to only Jupiter and Saturn. The new mission was called Mariner Jupiter/Saturn, or MJS. It was subsequently renamed Voyager about six months prior to launch. The rescoped mission was estimated to cost $250 million (through the end of Saturn operations), only a third of what the Grand Tour design would have cost.
Originally scheduled to launch twelve days after Voyager 2, Voyager 1's launch was delayed twice to prevent the occurrence of problems which Voyager 2 experienced after launch. Voyager 1's launch finally happened on 05 Sept. 1977 and was termed "flawless and accurate".
Although launched sixteen days after Voyager 2, Voyager 1's trajectory was the quicker one to Jupiter. On 15 Dec. 1977, while both spacecraft were in the asteroid belt, Voyager 1 surpassed Voyager 2's distance from the Sun. Voyager 1 then proceeded to Jupiter (making its closest approach on 05 March 1979) and Saturn (with closest approach on 12 Nov. 1980). Both prior to and after planetary encounters observations were made of the interplanetary medium. Some 18,000 images of Jupiter and its satellites were taken by Voyager 1. In addition, roughly 16,000 images of Saturn, its rings and satellites were obtained.
After its encounter with Saturn, Voyager 1 remained relatively quiescent, continuing to make in situ observations of the interplanetary environment and UV observations of stars. After nearly nine years of dormancy, Voyager 1's cameras were once again turned on to take a series of pictures. On 14 Feb. 1990, Voyager 1 looked back from whence it came and took the first "family portrait" of the solar system, a mosaic of 60 frames of the Sun and six of the planets (Venus, Earth, Jupiter, Saturn, Uranus, and Neptune) as seen from "outside" the solar system. After this final look back, the cameras on Voyager 1 were once again turned off.