As a lad, glued to the TV coverage of the Moon landing with 600 million others around the world, actor James Marsters was a little put out by how fuzzy the picture was.

"I was allowed to stay up late, and I was never allowed to stay up late," he remembers.

"I'd been told that this was very important. It seemed very cool at the time, but I couldn't understand why the picture was so bad. In my mind I thought it was going to look spectacular but it was all grainy. And then I got sleepy and got taken to bed," he laughs.

Back in July 1969, while the world was trumpeting the achievements of Neil Armstrong, it was Buzz Aldrin who 7-year-old Marsters was a fan of.

"The next day everybody was talking about Neil Armstrong and for some reason I thought Buzz was the cool guy. I never liked to go with what everyone else was doing. So I think just because everyone was talking about Neil I just naturally went with Buzz - it's a lot cooler name anyway."

Forty years on, Marsters finds himself playing his childhood hero in new television movie Moonshot: The Flight of Apollo 11 (July 26, 8.30pm, Prime), directed by Richard Dale, the man behind factual films like 2007's 9/11 The Twin Towers and the excellent documentary about the Apollo space missions, In the Shadow of the Moon.

Moonshot is a docu-drama containing never-seen-before archive footage and special effects that recount the lead-up to the Moon mission, the landing on July 20, and the return to Earth. It also reveals the intense competition that developed between Armstrong and Aldrin over who would be the first man to walk on the Moon.

Rather than being epic and grand, like many past space movies, the 90-minute tele movie is snappy and to the point with Armstrong's famous line, "One small step ...", almost glossed over in favour of the astronaut's descriptions of the Moon's surface.

"You could easily make it into a soap opera because there was such huge competiton," says Marsters. "They were all alpha dogs, and there was definitely a soap opera happening with them but we were just trying to tell the story as it happened and not trying to pump it up.

"These guys were not just the heroes we painted them as being, but in fact they were human beings," says the actor who's probably best known as Spike from TV series Buffy the Vampire Slayer.

Marsters prefers not to talk about Buffy, not that he's ashamed of it, it's just that he rates Moonshot as the most challenging and rewarding project he's done. So there's a lot to talk about, especially considering he got the chance to be Buzz Aldrin.

"He's like the coolest guy on Earth. He did something cooler than go to the Moon, he became a really cool person. And he saved himself," he says in reference to Aldrin's battle with alcoholism and depression.