Voyager 1 is at the edge of our Solar System and poised to leave us forever. Our Sun is constantly pushing a stream of charged particles, that we call the solar wind, outward beyond all the planets in our system. This area of solar wind is called the heliosphere. The space beyond the reach of that wind is called the interstellar medium by astronomers. As the solar wind gets farther away from the Sun, it slows down and can be affected more by interstellar phenomenon. This zone is called the heliosheath. The boundary between the heliosheath and interstellar space is known as the heliopause. The solar wind cannot be measured at all beyond that point.
Both Voyager spacecraft have travelled farther into space than any other object dispatched by humankind. They are both in the heliosheath and will soon cross the heliopause into deep space. This is expected by 2014 but since no other man made object has ever been that far, it is just a good estimate.
Voyager – The Interstellar Mission – [nasa.gov]
The twin Voyager 1 and 2 spacecraft continue exploring where nothing from Earth has flown before. In the 34th 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.
Voyager Time Line – [nasa.gov]
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