One of mankind's great dreams is the discovery of other planetary systems and the ability to travel to them, and a first step in fulfilling this dream is the unmanned probe represented by the Voyager Interstellar Mission. This is a difficult mission by any measure. Voyager I was launched September 5, 1977, and after it has been speeding along for more than 20 years, it is now 6.8 billion miles away from Earth traveling at nearly 51,000 miles per hour. In cosmic terms, that is only about 10 light hours away. However, the closest star to Earth is Proxima Centauri, which is 4.3 light years, or 25 trillion miles, away. If Voyager were pointed in the right direction, it is calculated that it would take some 74,000 years to make the trip. However, effective interstellar missions must occur on a human time scale preferably within an individual's lifetime -- which means a maximum of 40 years for a "slow" mission, and a far more desirable 10 years for a fast one (DiChristina & Sauls, 1999, 56).
In the beginning, Voyager was developed as a means of reaching the outer planets to gather data that had never been possible before. The Pioneer and Voyager spacecraft were sent to Jupiter, which Voyager 1 reached in March 1979 before going on to Saturn in November 1980. With its planetary mission completed, it continues to search for the edge of the solar system. Voyager 2 reached Jupiter in July 1979, Saturn in August 1980, and continued on to a rendezvous with Uranus in January 1986 and Neptune in August 1989. The Voyager missions to Jupiter and Saturn built on the data previously acquired during the Pioneer 10 and 11 flybys of Jupiter, and the new photographs of the planets, including their atmosphere, rings, and satellites, surpassed anything scientists expected. With the scientific data they accumulated, the Voyagers completely transformed our view of and knowledge about the giant planets. In addition, each Voyager carries a "...