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Voyager: The on-going mission

26 February 2013 Last updated at 17:40 GMT

Nasa scientist Dr Ed Stone describes the Voyager's on-going mission to reveal the secrets of the Solar System and, ultimately interstellar space.

In this clip from the BBC Four documentary, Voyager: to the final frontier, Dr Stone describes how the Voyager scientists have grown old as the decades-long mission just keeps on chugging.