Voyage of Discovery

Hi

The Voyager space craft need know introduction. These twin 700Kg probes were the first ever to visit all four gas giants and, are as of 2009 the most distant Human objects ever built. They are currently at a distance of 10.095 Billion miles from the Sun, on the very edge of the Solar System itself. Approaching the Heliopause and interstellar space. The Heliopause is the region marked out by the solar wind, and is essentially a bubble encompassing the solar system. Of course the History of the Voyager probes is a long and illustrious one.
Launched in 1977 the voyager probes were heading for the outer planets thanks to Newtonian mechanics. It had been calculated that a space probe with conventional rocket fuel could go no further than Jupiter. So a new method was needed if Voyager stood any chance of getting to the furthest reaches of the Solar System. Enter Gravity assist. Gravity assist is a convenient way of getting between planets with out the need for massive fuel stores. It works something like this, if you fly past a planet e.g. Jupiter at the correct angle the planets gravity takes the space robe and, shoots it off in a different direction with an increased burst of speed. Also conveniently at the time of the voyager launch in the seventies, all four gas giants were in a rare 150 year planetary alignment. Which meant that by using gravity assist if the space craft got the correct trajectory as it left each planet, it would be shot of for an encounter with the next planet out and so on.
So with a viable way to get to the outer planets voyager was off!
Voyager 1 reached it's first Gas giant target of Jupiter in march 1979. 2 years after launch. Voyager's closest approach was at a distance of 217,000 miles. Voyagers pass revealed incredible detail about Jupiter it's moons and atmosphere. Among many discoveries Voyager imaged very faint rings around Jupiter. Imaged with unparalleled detail the atmosphere of Jupiter. And perhaps most importantly showed that the four galleon satellites were far from dull! Io was shown to be more active than Earth with many sulphurous volcanoes. And Europa was discovered to have a entire water ice covering, which perhaps covers a warm liquid water ocean! which maybe could have black smokers (volcanic vents), that provide home to microbial life! A lot of speculation there but it's not completely impossible. After the huge success of the first fly by the stage was set for Saturn.
The gravity assist with Jupiter was successful and in February of 1980. 3years after launch Voyager arrived at Saturn. This time Voyagers closest approach was from 77,000 miles. At this distance Voyager unveiled complex structures in Saturn's expansive rings, analysed the Saturnian atmosphere. And again showed that Saturn's moons were surprisingly active. Titan was unique in that it was proved to be the only moon with an atmosphere. And Enceladus had Ice geysers ,that were and still are so prolific they contribute to the ring system around Saturn!
The next fly by was with the planet Uranus (No puns!). Voyager passed Uranus in January 1986, at a distance of 81,000 km. Sadly Uranus was fairly bland and there was little to see in it's Methane clouds. This was a major disappointment for the mission scientists. But Neptune was still to go.
The Final planet in Voyagers mission was Neptune, which was passed in August 1989. Nearly 20 years after the original launch. In contrast to Uranus Neptune was much more interesting. Like Jupiter Neptune was discovered to have a great dark spot and, the fastest winds in the solar system clocked at nearly 1000 mph! Also Neptune's largest moon Triton was imaged with Nitrogen geysers miles high! Such was the frigid temp of this moon, that Nitrogen which makes up the gas of are atmosphere on Earth is frozen solid ice.
Voyager now passed all the planets and with no possibility of reaching Pluto drifted of into interstellar space. It's last image of the solar system was a sort of “Family portrait” ( to right)taken in 1990, with all the planets visible and Earth less than a pixel across!
So that was a brief history of the Voyager probes and there amazing journey to the very edge of the Solar system. The voyager probes now at the very limits of communication with earth, will continue to drift into the void of interstellar space in silence. And in roughly a few million years it is believed they will pass some of the nearest stars!
Thanks for reading.

Kyle