More than 30 years after they left Earth, NASA's twin Voyager probes are now at the edge of the solar system.
Not only that, they're still working. And with each passing day they are beaming back a message that, to scientists, is both unsettling and thrilling.
The adventure began in the late 1970s when the probes took advantage of a rare alignment of outer planets for an unprecedented Grand Tour. Voyager 1 visited Jupiter and Saturn, while Voyager 2 flew past Jupiter, Saturn, Uranus and Neptune. (Voyager 2 is still the only probe to visit Uranus and Neptune.)
The twin Voyager 1 and 2 spacecraft continue exploring where nothing from Earth has flown before. In the 33rd year after their 1977 launches, they each are much farther away from Earth and the Sun than Pluto. Voyager 1 and 2 are now in the "Heliosheath" - the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar gas. Both spacecraft are still sending scientific information about their surroundings through the Deep Space Network (DSN).
The primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there -- such as active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings -- the mission was extended. Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets. The adventurers' current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun's domain. And beyond.
Read and learn more at : Mission Objective and Voyager Set to Enter Interstellar Space
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