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.

He jokes that Aldrin's recent collaboration with rapper Snoop Dogg on the song Rocket Experience is further proof of the 79-year-old's enduring coolness.

It was because of Aldrin's highly strung personality that he was not given the nod ahead of the more cool, calm and collected - if a little boring - Armstrong to be the first man to walk on the Moon.

"I think Buzz should have got out first though, man," offers Marsters. "You know, the commander of the mission always stayed behind, every time, up until this one. I understand that Armstrong was probably more stable and he would probably handle the worldwide fame better, and as it turns out Armstrong has pretty much clammed up, and I don't blame him, but at the same time if they'd have chosen Buzz there'd be a more talkative first man to the Moon."

While Aldrin is the most competitive of the three Apollo 11 astronauts he's also the biggest team player.

"He just wanted to be the best astronaut ever because he thought - and I guess I'm speaking for someone who is still alive, which is a bit dicey - but to my understanding, he thought his father would finally tell him, 'Good job, son,' which he never said. That sort of thing will drive you to excel."

Moonshot manages to create a claustrophobic atmosphere, much like you'd imagine life in the crammed capsule to be like. Dale and his film crew used small cameras that, for the first time in the making of a movie of this type, enabled filming to be done using sets that were the actual size of the Apollo 11 capsule.

"Up until now they have always had to shoot with cameras that were very large, even the capsule in [the 1995 Tom Hanks movie] Apollo 13, which is a great film, was three times as big as it really was, so it kind of looks comfortable. It almost looks like it was a cakewalk to go to the Moon," says Marsters.

Which it wasn't, of course. And as farfetched as it sounds, by playing the part of Aldrin, he says he can appreciate what the astronauts went through to get to the Moon.

"They thought they only really had a 50/50 chance of living, and I don't know if they were afraid, they might have been resigned to their fate, but it was definitely not a cake walk.

"It's akin to going up Everest. It's really uncomfortable and it's not even that healthy. It's just one stinking miasma the whole time but you're doing something you really want to do so you put up with it. So what was out the window was definitely worth it but good God, what you have to go through inside that capsule."

What: Moonshot: The Flight of Apollo 11, about the journey to the Moon and back

When: Prime, July 26, 8.30pm

Who: James Marsters, as astronaut Buzz Aldrin. Marsters is best known as Spike the Vampire in Buffy The Vampire Slayer