|Launch vehicle||Titan IIIE-Centaur|
|Launch date|| 1977 August
Voyager 2 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.
Message in a BottleEdit
Each Voyager has mounted to one of the sides of the bus a 12-inch gold-plated copper disk. The disk has recorded on it sounds and images of Earth designed to portray the diversity of life and culture on the planet. Each disk is encased in a protective aluminum jacket along with a cartridge and a needle. Instructions explaining from where the spacecraft originated and how to play the disk are engraved onto the jacket. Electroplated onto a 2 cm area on the cover is also an ultra-pure source of uranium-238 (with a radioactivity of about 0.26 nanocuries and a half-life of 4.51 billion years), allowing the determination of the elapsed time since launch by measuring the amount of daughter elements to remaining U238. The 115 images on the disk were encoded in analog form. The sound selections (including greetings in 55 languages, 35 sounds, natural and man-made, and portions of 27 musical pieces) are designed for playback at 1000 rpm. The Voyagers were not the first spacecraft designed with such messages to the future. Pioneers 10 and 11, LAGEOS, and the Apollo landers also included plaques with a similar intent, though not quite so ambitious.
Onward and OutwardEdit
Rechristened the Voyager Interstellar Mission (VIM) by NASA in 1989 after its encounter with Neptune, Voyager 2 continues operations, taking measurements of the interplanetary magnetic field, plasma, and charged particle environment while searching for the heliopause (the distance at which the solar wind becomes subsumed by the more general interstellar wind). Through the end of the Neptune phase of the Voyager project, a total of $875 million had been expended for the construction, launch, and operations of both Voyager spacecraft. An additional $30 million was allocated for the first two years of VIM.
Voyager 2 is speeding away from the Sun at a velocity of about 3.13 AU/year toward a point in the sky of RA=338 degrees, Dec=-62 degrees (-47.46 degrees ecliptic latitude, 310.89 degrees ecliptic longitude).