With the title role in the heralded crime drama "Luther" and a pivotal turn in the blockbuster "Thor" -- as well as recurring roles in such TV hits as "The Office" and "The Big C" -- there's no question that actor Idris Elba has been one of the most in-demand actors in Hollywood the past couple of years.

Yet as busy as he's been, when someone like director Ridley Scott comes calling, Elba said he doesn't hesitate to clear his schedule. The acclaimed British actor, who previously worked with Scott on "American Gangster," told me in a recent interview that "there was very little deliberation" on whether to sign on to "Prometheus," especially after some flattering words from the legendary filmmaker.

"He called me and said, 'I'm doing this film, a sci-fi project and there's character in it -- the captain -- I can't think of anyone else who could play him except for you. I think you'd be amazing in it.' That was the end of the conversation," Elba recalled. "I read the script and said 'yes.'"

As to why Scott felt the actor, 39, was perfect for the role of Janek in "Prometheus" -- a rough sea-captain-type whose main mission is to protect the ship and its crew -- still somewhat remains a mystery to the Elba.

"It's a good question since I played a drug dealer in the last film for him," Elba said with a laugh. "What he was drawing his inspiration from I don't know."

The ship Janek is piloting is called the Prometheus, which will take a crew headed by scientist Elizabeth Shaw (Noomi Rapace) to a desolate moon on the darkest outer-reaches of the universe after Shaw discovers a clue to the origins of mankind on Earth. But when the crew gets there after a two-year trek, they discover not only clues to their past, but a horrifying threat to the Earth's future.

Opening in 2D, 3D and on IMAX screens Friday, "Prometheus" also stars Logan Marshall-Green as Charlie Holloway, Shaw's scientist boyfriend; Michael Fassbender as the ship's android, David; Guy Pearce as Peter Weyland, the founder of the conglomerate whose corporation finances the trillion-dollar mission; and Charlize Theron as Meredith Vickers, a forceful Weyland Corp. executive who accompanies the crew on the ship.

While the crew and Weyland Corp. are all tied together on the mission, Elba said Janek's purpose is to stand independent from them -- or at least as long as he can.

"Janek is very much a blue collar man and straight down the line kind of guy. He's not a scientist or a Weyland Corp. best boy, he's just a captain who flies these huge spaceships across the universe," Elba explained. "As the film progresses, though, Captain Janek has to make a decision where he has to question himself. It's one of these moments where you'll see a man go, 'Hold on a minute here, I'm not a part of this and now I have to get involved.' It's quite an interesting story for me."

Having worked on action and/or sci-fi films before, Elba well knows that audiences enjoy a lot of visual razzle dazzle in their film diets. But in the case of director Kenneth Branagh with "Thor" last year and now Scott with "Prometheus" (plus he has "Thor 2" and Pacific Rim" coming up), Elba stressed how important it is to filmmakers and actors to respect the intellect of their audiences.

"There are a handful of filmmakers who not only want to challenge their audiences, they want them to watch their films more than once or twice," Elba observed. "Trends will tell you that people watch certain films three of four times now, and the reason for that is they probably didn't catch everything the first time. That's a good sign, when a film can be really entertaining but also can also challenge viewers mentally. 'Prometheus' certainly has elements that speak to that."

Elba hopes that one particular element audiences can't get enough of are the awe-inspiring sets -- many of which Scott had built to scale. That includes the interior of the Prometheus, which of course is Elba's personal playground as the ship's captain.

"I've never flown a spaceship before -- believe it or not," Elba cracked. "But, I can honestly say, if I go into a spaceship now, based on the reality of Ridley's filmmaking, I'd probably have a little bit more of an idea how to do it."

"The cockpit I was working in was so realistic. It was based on real logistics of how you would take something that weighs 4,000 tons and flew it into space," Elba added. "It's really helpful to have a director who puts his actors into a real as environment as you can get. You see it from a point-of-view that is so real that you forget you're acting."