Doug Naylor, co-creator/writer

Rob Grant and I were writing a Radio 4 comedy show called Son of Cliché in which there was a recurring sketch called Dave Hollins: Space Cadet, a parody of Alien, with a lone survivor and a computer, voiced by Chris Barrie. I remember watching [70s sci-fi comedy movie] Dark Star and saying: “It’s crazy no one’s done a sitcom like that.” Then we went to the pub and forgot all about it.

Years later, Rob and I were writing for Spitting Image, and we wanted to do a sitcom. We had been introduced to Ray Galton and Alan Simpson, who wrote Steptoe and Son and Hancock’s Half Hour. They told us how they created Steptoe: they just started to write. First they just had two blokes, then they became brothers, then father and son, then rag and bone men. We were like: “Wow! Aren’t you supposed to have your goals, obstacles and character flaws all mapped out?”

All space shows have a genius computer, so we made ours, Holly, an idiot

My parents had a cottage halfway up a mountain in Wales, so Rob and I went there for a week to write. We didn’t want aliens, so we made the character Rimmer a hologram. He was a complete jobsworth, so Lister is the opposite, a slob. All space shows have a genius computer, so we made ours, Holly, an idiot. We also wanted someone cool, like they’d evolved from cats – hence the Cat.

It went off to BBC comedy producers John Lloyd and Paul Jackson, who both loved it. John said: “I’ll be disappointed if you cast any of the Oxbridge people. It needs to be completely fresh.” He’d just done Blackadder and I think he was worried we would steal his cast.

We thought: “How can this fail?” But the BBC rejected it three times. Alan Rickman and Alfred Molina liked the script so we considered casting them as Rimmer and Lister. Rickman wanted to be Lister because he thought playing Rimmer would be too easy. In the end, Craig Charles and Chris Barrie just seemed a better double act.

We had a great fantasy that the original crew would be hugely famous comedy names – like Ronnie Barker, Leonard Rossiter and John Cleese – so that people would be going: “I must tune into this.” Then they all die after 10 minutes and you’re left with this bunch of unknowns. “Craig Charles? Never heard of him.”

Oxbridge not allowed … a scene from series II. Photograph: UKTV

Craig Charles, played Dave Lister

I was a regular on Saturday Live, Channel 4’s riotous alternative comedy show. There was Ben Elton, Fry and Laurie, Harry Enfield, Adrian Edmondson and Rik Mayall. They were all quite a bit older than me, and all friends. I was the odd one out, doing controversial, edgy poems about Margaret Thatcher and South Africa.

Saturday Live’s producer, Paul Jackson, was leaving to do this curious little project on BBC2 called Red Dwarf, a science-fiction sitcom set in space. They had a lot of trouble getting it off the ground. The head of comedy at the BBC – a guy called Gareth Gwenlan – was a mainstay of sofa-based sitcoms. He said it’ll only work if you have a sofa and the camera pans out through the windows to show you’re on a spaceship. Rob and Doug said: “You don’t have sofas on spaceships.” He said: “That’s why it won’t work.”

We just play caricatures of ourselves – it’s very method

But they eventually got the money through BBC North West. I said to Jackson: “Got any parts going?” He said: “No, but I would like you to read the script and tell me if the part of the Cat is racist.” He sent me the script and it was just brilliant. I said: “The Cat’s not racist, he’s really cool. Can I be Lister?” His reply began with an F and finished with two Fs. But I begged and begged for an audition, and in the end he relented.

I’d never acted before. None of us had really. Chris Barrie was an impressionist. I was a standup poet. Rob Llewellyn was in an awful comedy troupe called the Joeys and Danny John-Jules was a dancer. We just play caricatures of ourselves – it’s very method. There’s an awful lot of Lister in me, a lot of Rimmer in Barrie, although he’d hate me for saying it. There’s plenty of the Cat in Danny, unfortunately. And Rob is just full of middle-class angst and guilt, so perfect for Kryten.

I don’t think Alan Rickman and Alfred Molina lost too much sleep over not getting cast. They went off to fantastic film careers and here I am still peddling this old mining ship in space.

• Red Dwarf: The Complete Series I-VIII is available on Blu-ray.