The Voyager missions are now in their 25th year and are a shining example of what NASA used to be capable of. It is hoped that one or both spacecraft will soon reach the heliopause, the outer reaches of our solar system where the solar winds cease and interstellar forces dominate. For a timeline of the missions, check out the story at planetary.org. The link “Voyager’s Photo Legacy” and this NASA JPL link are good sources for some of the images sent by the spacecraft. The discussion at slashdot.org is pretty interesting and is also interspersed with more links to explore.