Jet Propulsion Laboratory (U.S.). Office of Engineering and Mission Assurance.

Project Voyager was a dual spacecraft long-range mission that conducted a "Grand Tour" of the Outer Planets. The project, originally called "Mariner Jupiter/Saturn 1977" (MJS77) was approved by NASA and Congress in June 1972. MJS77 was renamed Voyager in 1977, slightly before the first launch date. The two Voyager spacecraft were launched in August and September 1977. Voyager 1 made its closest encounter with Jupiter on March 5, 1979; Voyager 2 reached Jupiter on July 9, 1979. Voyager 1 reached Saturn on November 13, 1980. Voyager 2 reached Saturn on August 26, 1981. Voyager 2 then headed towards Uranus and Neptune, while Voyager 1 traveled north of the Ecliptic plane after its Saturn encounter. Voyager 2 encountered Uranus on January 24, 1986 and Neptune on August 25, 1989. Both Voyager spacecraft continue to send back scientific telemetry, twenty-two years after leaving Earth and will continue doing so until the power runs out in both spacecraft, around 2017.

The two Voyager spacecraft were the third and fourth human artifacts to escape entirely from the solar system. Pioneers 10 and 11, which preceded Voyager in outstripping the gravitational attraction of the Sun, both carried small metal plaques identifying their time and place of origin for the benefit of any other spacefarers that might find them in the distant future.

With this example before them, NASA placed a more ambitious message aboard Voyager 1 and 2, a kind of time capsule, intended to communicate a story of planet Earth to extraterrestrials. The Voyager message is carried by a 12 inch gold-plated copper disk containing sounds and images selected to portray the diversity of life and culture on Earth. The contents of the record were selected for NASA by a committee chaired by Carl Sagan of Cornell University. In fact the whole idea of the disk was Sagan and his wife's, Ann Druyan. Dr. Sagan and his associates assembled 115 images and a variety of natural sounds, such as those made by surf, wind and thunder, birds, whales and other animals. To this they added musical selections from different cultures and eras plus spoken greetings from Earth's human inhabitants in 55 languages along with printed messages from President Carter of the U.S. and U.N. Secretary General Waldheim.

Each record was encased in a protective aluminum jacket, together with a cartridge and a needle. Instructions, in symbolic language, explain the origin of the spacecraft and indicate how the record is to be played. The 115 images are encoded in analog form. The remainder of the record is audio, designed to be played at 16 2/3 revolutions per minute. It contains the spoken greetings, beginning with Akkadian, which was spoken in Sumer about six thousand years ago and ending with Wu, a modern Chinese dialect. Following the section on the sounds of Earth, there is an eclectic 90 minute selection of music, including both Eastern and Western classics and a variety of ethnic music.

As the Voyager Spacecraft leave the solar system, they will find themselves in empty space. It will be forty thousand years before they make a close approach to any other planetary system. As Carl Sagan has noted, "The spacecraft will be encountered and the record played only if there are advanced space-faring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet".

From the description of Voyager Interstellar Record Collection, 1976-1977. (Jet Propulsion Laboratory Library and Archives). WorldCat record id: 733100152