Brad Pitt’s new space film Ad Astra is his most challenging yet

The actor made the comments when the film premiered at the Venice International Film Festival

Brad Pitt walks the red carpet ahead of the "Ad Astra" screening during the 76th Venice Film Festival at Sala Grande in Venice, Italy. Getty Images

Pitt walks the red carpet ahead of the "Ad Astra" screening. Getty Images

Pitt poses on the red carpet. Reuters

Pitt, Ruth Negga, Director James Gray and Liv Tyler walk the red carpet. Getty Images

Pitt talks to Gray and Tyler at the the "Ad Astra" screening. Getty Images

Pitt walks the red carpet. Getty Images

Pitt signs autographs. Reuters

Pitt poses for selfie photos. AFP

Pitt signs autographs for fans. EPA

Pitt signs autographs on the red carpet. Getty Images

Pitt arrives for the screening of the film "Ad Astra". AFP

Pitt walks the red carpet ahead of the "Ad Astra" screening. Getty Images

Brad Pitt has fought in wars, pulled off robbery heists and confronted rivals in the boxing ring during his career, but the Hollywood star says his most challenging film yet is playing an astronaut on a life-saving mission in the space epic Ad Astra.

To be released in UAE cinemas on Thursday, September 19, the film has the 55-year-old actor taking audiences to the far reaches of the solar system in his role as Roy McBride, after a new threat causing disastrous power surges threatens Earth.

McBride sets off to find his pioneering astronaut father, played by Tommy Lee Jones, who went missing more than a decade earlier while on a mission to Neptune.

Set in the near future, where mankind has set up living stations and research centres on the moon and Mars, the film follows McBride as he makes his way into the vast abyss through spectacular landscapes and empty space.

The trip soon becomes a journey of self-discovery.

Speaking before the film's glittering red carpet premiere on Thursday at the Venice Film Festival, Pitt – who also produced the film – described Ad Astrada as the most challenging film of his career.

"The story ... is so delicate and any clip of a frame too early or music cue or voiceover could easily tip the thing over or be too much or be too obvious,” he said.

“It was a constant effort just to try to maintain this balance and try to keep this story unfolding in a very subtle and delicate way."

Pitt called the film "a very intimate journey of the soul," which at the same time mulls the possibility of extraterrestrial life.

"I like to believe there is [life] somewhere,” he said.

“To what degree, more advanced than us, less? Who knows ... Would we find that in our lifetime, don't know. Not too concerned," he said of his own beliefs.

McBride narrates his history and relationship with his father throughout the odyssey, where he faces challenges as well as enemies in an inhospitable and lonely environment.

"We decided to try and tell the smallest possible story in the biggest possible tapestry ... The tiny becomes the universal," said director James Gray.

Ad Astra is one of 21 movies competing for the top Golden Lion prize at the festival, which runs until Sept. 7.

Sharing space tips with George Clooney

Venice is no stranger to screening space movies, having previously premiered the Oscar-winning Gravity, starring Pitt's frequent co-star and friend George Clooney, as well as last year's First Man, about the 1969 moon landing.

Asked if he had exchanged any space movie tips with Clooney, Pitt referenced the process of hanging from wires during such shoots, saying: "George and I exchanged some discomfort stories."

Ad Astra, which also stars Liv Tyler, Ruth Negga and Donald Sutherland, is considered one of the must-sees during the festival, which is considered an important launch pad for the awards season.

Asked whether the role could perhaps win him his first best actor Oscar, Pitt said: "Man, I just want to get this film out ... it's a challenging film, it's subtle.

"It's operating on many cylinders, it has something to say about who we are, a soul if you believe in that, what’s our purpose, why do we hang on, keep doing. So I am really curious to see how it lands."

The critics love the film

Critics praised the film's stunning cinematography and soulful nature.

In its five star review, The Guardian newspaper said the film "pitches from full-blown horror to the thunderclap of closure."

Screen Daily said Pitt's performance was "full of pained melancholy" while Variety said the story was "held together by Pitt's stalwart presence."