For a show with a self-proclaimed ‘five-year mission’, Star Trek hasn’t done badly. Gene Roddenberry’s ‘Wagon train to the stars’ is celebrating its 50th anniversary, although, as Marcus Berkmann’s entertaining and irreverent history points out, things could have been very different. Roddenberry’s initial idea was for a troupe of disparate 19th-century adventurers to explore the undiscovered corners of the New World in a grand airborne dirigible.