HOLLYWOOD — Wearing a trucker hat, battered blue jeans and an air of breezy confidence, Chris Pine walked through the Paramount Pictures studio lot like he owned the place but felt no particular need to show anyone the deed in his pocket.

It's precisely that mix of fighter-pilot cockiness and surfer-dude Zen that you would expect from an actor who, as the leading man in "Star Trek," has taken on the biggest challenge of any popcorn-movie star this summer: How to play James T. Kirk without imitating the role's originator, William Shatner?

"That's it right there; that's the challenge," Pine said of the film, which opened Thursday. "If I can do that, then we're good."

The Los Angeles native has apparently done just that, at least according to early reviews and a positive industry buzz that frames "Star Trek" as this year's "Iron Man," a sleek summer movie with intense action, wit and surprising buoyancy considering all the heavy equipment taking flight.

The film begins on the day Kirk is born — the same day his father dies 12 minutes into his first command as a starship captain.

It follows Kirk through his daredevil youth and his Starfleet Academy career as a rakish Romeo with a need for speed and no love of regulations. Then it's off into space, where he and the rest of the crew must tangle with an angry Romulan named Nero.

Paramount, expecting big things, has already announced a sequel for 2011. Still, there are no sure bets in Hollywood, and while the crew of the USS Enterprise may live in the future, they may seem like ancient history to young moviegoers.

This "Star Trek," though, is not your grandfather's starship. Director J.J. Abrams ("Mission: Impossible III" and television's "Lost") grew up as a "Star Wars" fan and decided that Gene Roddenberry's venerable space-frontier epic could use a bit of the George Lucas mojo — yes, that sound you hear is Trekkers gagging on their Romulan ale.

This new version has intense dogfights, a sprinkling of exotic aliens, major dollops of humor and even a bit of an icy tribute to "The Empire Strikes Back."

Zachary Quinto of NBC's "Heroes" is in as Spock and, thanks to some time travel, Leonard Nimoy appears as the Vulcan in his advanced years. The cast includes Simon Pegg, Eric Bana, Winona Ryder and, startlingly, a cameo by Tyler Perry.

But "Trek" will fly or fail based on the man in the captain's seat: Pine.

"He is our star," Abrams said, "and it was an intense challenge to take on a role that was so defined for so long by Shatner."

Pine's biggest impact was in Joe Carnahan's 2006 Las Vegas underworld tale "Smokin' Aces." Now comes the career-shaping role in "Star Trek," and his name has been floated to step into another major franchise, perhaps "The A-Team" remake or wearing the emerald power ring in the planned "Green Lantern" film.

With "Trek," Pine says he wasn't a loyal fan growing up but that he has marveled at its sense of "optimism and unity" and, at the risk of sounding corny, he said that, like the original series in the 1960s, this revival finds itself reaching for hope amid real-life global crisis.

In the film, Pine has a loose-limbed swagger that at times recalls the way Shatner would slump with style in the captain's chair. There are also moments in which Pine stretches or pops a word in the staccato manner of his predecessor, but the young actor is doing much less mimicry than some of the other cast members, such as Karl Urban, who as Dr. McCoy gleefully imitates the late DeForest Kelley's Southern sourpuss rants.

In his search for Kirk, Pine got a boxed set of the TV series and binged.

"I realized pretty quick into that exploration that I was doing myself a disservice," he said. "All I was doing was creating this monolithic task. There was no sense in trying to re-create what Shatner had done because it was so specific. He was unique, singular; it was his take. I did spice my performance with some of his straight-spined, almost ballet way of moving."

He adds: "Shatner will forever be James T. Kirk. There's something set in stone about that. That actually takes pressure off me. I'm going my own way. My name is not William Shatner."