1. Peter Capaldi Considered for: Sisko in Star Trek: Deep Space Nine 20 years before he'd achieve sci-fi stardom as the 12th Doctor, Capaldi tried out for the part of DS9's Sisko. Back in 1992, he went up against not just Avery Brooks, but also Art Malik, Keith Allen(!) and Anthony Head, some five years before he would book the role of Giles on Buffy the Vampire Slayer. 2. Linda Hamilton Considered for: Janeway in Star Trek: Voyager A few years after revisiting her role as Sarah Connor – herself a sci-fi icon – in Terminator 2: Judgment Day, Hamilton was apparently considered to play Voyager's Janeway. It seems producers were keen to hire an actress with prior cult credentials. Also under consideration were Lynda Carter of Wonder Woman fame, Buck Rogers veteran Erin Gray and Lindsay Wagner, star of The Bionic Woman. As well as... 3. Nicola Bryant Considered for: Janeway in Star Trek: Voyager Bryant played Peri Brown, companion to first Peter Davison's fifth Doctor and later Colin Baker's sixth on Doctor Who from 1984 to 1986, and was a name on the Janeway shortlist. Interestingly, Geneviève Bujold originally landed the part, but abruptly quit after filming just a few scenes from the first episode, citing the show's demanding schedule. She was replaced by Kate Mulgrew, who absolutely made the part her own. 4. Edward James Olmos Considered for: Picard in Star Trek: The Next Generation He'd later play the role of commanding officer William Adama in Syfy's reimagining of Battlestar Galactica, but Olmos reportedly turned down the part of Picard because, back in the late '80s, he was keen to focus on film and stage work. 5. Yaphet Kotto Considered for: Picard in Star Trek: The Next Generation Best known for playing Bond villain Kananga in 1973's Live and Let Die, as well as for his role of Parker in Alien (1979), Kotto could have been Trek's first captain of colour after auditioning for TNG, but he was passed over in favour of Patrick Stewart. He went on to land a career-defining role in groundbreaking cop show Homicide: Life on the Street, playing Lt Al Giardello from 1993-1999, so all's well that ends well. 6. Jack Lord Considered for: Kirk in Star Trek: The Original Series Star Trek without The Shat? Unthinkable! But he wasn't Gene Roddenberry's first choice for the part of James Tiberius Kirk. That honour went to Jack Lord, then best known as the first actor to play James Bond's CIA ally Felix Leiter (in 1962's Dr. No). But Lord lost out after demanding part ownership of the Trek franchise. Interestingly, Shatner later followed suit and was actually awarded five per cent ownership, so Lord presumably asked for a larger chunk. Two years later and Lord secured the most significant role of his career, playing Steve McGarrett in the original Hawaii Five-O – so again, things probably worked out for the best. 7. Chris Pratt Considered for: Kirk 2.0 in Star Trek (2009) Moving on to the movies – and as if it weren't already difficult enough to tell them apart, Chris Pratt actually went up for the role eventually nabbed by Chris Pine in JJ Abrams's shiny Trek reboot for the big screen. In another major fork-in-the-road moment, if Pratt had been cast, he might never have become spacefaring hero Peter Quill /Star-Lord in Marvel's Guardians of the Galaxy. AND THEN WHERE WOULD WE BE? 8. Mike Vogel Considered for: Kirk 2.0 in Star Trek (2009) Another wannabe Jim Kirk, Vogel is best known for a lead role on the TV adaptation of Stephen King's Under the Dome (2013-2015) and for film appearances in the Texas Chainsaw Massacre remake (2003) and Cloverfield (2008). He got down to the final two for Kirk, but was pipped to the post by Pine. Vogel lost out to another of Hollywood's famous Chrises – this time Chris Evans – a year later when Marvel was casting Captain America. 9. Joshua Jackson Considered for: Kirk 2.0 in Star Trek (2009) Jackson would have been enjoying a bit of a career resurgence in 2008/9, having just launched his FOX sci-fi series Fringe. But it wasn't enough to secure the erstwhile Pacey Witter the part of Kirk. Like many of the names on this list, he's not done half bad since his brush with Trek, following up Fringe with Golden Globe-winning drama series The Affair. 10. Nigel Havers Considered for: Janeway in Star Trek: Voyager Though Janeway was always intended to be female, some male actors were brought in to audition, in case Paramount got cold feet over casting a woman in the lead. (This was in the mid '90s – seriously, guys?) Havers read for the part, but thankfully the idea of Janeway as a dude never took off and the franchise instead gave us its first female Captain. And about time too!