The Voyager I probe is one of the most famous spacecraft ever to have been launched. This probe is the farthest man-made object ever from earth, an still continues to operate till date. It will keep working until is hits a celestial body or plunges into the fires of a star.
Voyager I was built for a Grand Tour of the solar system that was proposed in the early 1960s. Because of the information sent back form the Pioneer 10 probe, the scientists at NASA were able to design a better probe. It was actually a part of the Mariner series of missions, but the name was changed to Voyager afterwards. It consists of 16 thrusters, 3 gyroscopes, referencing instruments and a host of other paraphernalia which allow it to study other celestial bodies and to relay messages back to Earth. (Right): A picture of Voyager I.
Power for the Voyager I comes from a set of three radioisotope generators, which consist of a lump of radioactive metal which heat a set of wires to power the various systems of the probe. The fuel has a half-life of 87.7 years, but by 2025, it will not generate enough electricity to power all its instruments. Voyager was the first probe to send back detailed pictures of Saturn and Jupiter and their numerous moons. (Left): The Golden Record attached to Voyager I.
Voyager I took the first every photograph of the solar system from outside, which shows Earth as a pale, blue dot. Afterwards, all cameras and their software were deactivated to conserve power. Voyager I is equipped with a record called Golden Record, which has sounds of human life on Earth. This was intended in case any extra-terrestrials retrieved the probe. (Right): The Great Red Spot of Jupiter photographed by Voyager I.
On September 2013, NASA confirmed that Voyager I had crossed into interstellar space. It is the first spacecraft to have done so. Assuming the probe does not crash into any cosmic bodies an retains its current velocity, it will reach the Oort Cloud in 300 years and will pass through it in about 30,000 years. In 40,000 years, it will pass within 1.6 light years of the star Gliese 445 and will then keep going in the Milky Way.