Voyager 1 was 25 years old yesterday. Generations from now will recognise the Voyager program as one of the Mankind's great expeditions of discovery. I remember the wonderful excitement I felt when the images taken by Voyager 2 as it passed Jupiter and Saturn were first released in the early Eighties. Since then, subsequent high tech probes seem to me to have lacked the sense of adventure of Voyager. We've had comet chasers and Mars surveyors and the Gallileo program and all, while scientifically bountiful, have not captured the imagination in the same way as Voyager. But then again maybe it's just me getting older and more cynical.