On September 5, 1977, the
Voyager-1 probe was launched (2 weeks
after the launch of Voyager-2). The immediate mission of the two craft was to fly by and investigate Jupiter and Saturn, although the trajectory of Voyager-2 allowed it to also then visit Uranus and Neptune.
In January 1979 Voyager-1 encountered Jupiter and its inner moons, sending back a wealth of data about the largest planet in our solar system. In November 1980 Voyager-1 encountered Saturn and its inner moons. Its trajectory was such that the Saturn encounter sent the tiny probe away from the orbital plane and in the direction of interstellar space.
While most of the craft's systems have now been shut down in an effort to conserve power - not to mention hardware failure - the little craft is still operating.
In February 1998 Voyager-1 officially became the furthest man-made object in the Solar System when it "overtook" Pioneer-10.
In December 2004 Voyager-1 crossed the Termination Shock and entered the heliosheath - the point at which our Sun's solar wind and influence balances with the interstellar gasses of the galaxy - at a distance of 94 AU (94 times the Earth-Sun distance of 150 million km).
In August 2008 Voyager-1 exited the heliopause and entered interstellar space, becoming the first man-made object to leave our solar system entirely - a distance of 121 AU.
And the probe
is still going. It is currently over 15.46
billion miles (166 AU) from Earth, travelling at an estimated speed of a little over 38,000 mph
It is a testament to human ingenuity and science. While there will be future space projects that overshadow the Voyager missions in complexity and achievement, there will be few that are, or will be, so profound as these two little craft.