For the comic strip see; Voyager (comic strip).
Voyager was a shadowy figure who haunted the Doctor's dreams. Astrolabus stole some charts from Voyager and so he blamed the Time Lords. He ordered the Doctor to recapture them for him. (DWM: Voyager)
When the Doctor caught him, Voyager killed Astrolabus. (DWM: Once Upon a Time Lord)