"You know, those things are very finicky - you can never tell," Damon says of his Oscar chances. "What I hope is that people like the movie as much as they like the book. Hopefully, we're able to hang on to all the things that are so enjoyable about the book. If we can do that, I think we did our job."

Astutely adapted by screenwriter Drew Goddard, it's based on the novel by science geek Andy Weir, whose 2011 self-published title turned into a bestseller. Damon stars as Mark Watney, a botanist left behind on a mission to Mars when he is lost in a dust storm and presumed dead by the crew led by Jessica Chastain, who also appeared in .

But Damon was on his own for most of his scenes as his character uses his scientific knowledge to survive in the harsh Martian environment and wait for rescue.

"It was great working with Jessica; unfortunately we only got two or three scenes together," he says of Chastain. "The one drawback to [doing] this movie is that there're all these great actors that I didn't get to do any scenes with. Jeff Daniels and Chiwetel [Ejiofor] - all these guys, I love their work - and I didn't even see them."

Damon chuckles: "They're in a whole other movie."

In that sense, his experience was akin to that on : "When I arrived on the set … they'd shot most of the movie and I came on for the last six weeks," he says.

"On [ ], when I arrived, they'd already wrapped 55 actors. The whole mission control side of the movie had been shot already - so it felt like ."

So does he find it more challenging to act alone or with other actors? "It depends on the actors," he quips, laughing. "I only have a few scenes with other actors. But you know, even when you're shooting a scene alone, you're still surrounded by 50 people - they're just not on camera with you.

"Also, the Mark character, unlike Robinson Crusoe, is in a habitat but there're cameras everywhere. He's behaving as if these [videos] are going to be viewed someday. He's leaving this log potentially for future astronauts to understand what he was trying to do and how he was trying to survive. So he is aware that he's being watched."

Incidentally, the presence of multiple cameras is a key part of Scott's approach to filmmaking. The director usually has four cameras rolling at the same time, a practice that also reminds Damon of his experience shooting .

"Spielberg probably had, I don't know, more than four cameras going. I would sit next to him at the monitors - he had a bank of monitors - and he would say, 'OK, play back', and he would literally point and go, 'OK, here, now we're here, now we're cutting to here'. He would just point and have the whole thing cut out in his head, basically in real time."

Damon has collaborated with a number of directing geniuses - Spielberg, Nolan, Martin Scorsese, Steven Soderbergh, Clint Eastwood and the Coen brothers among them - with the aplomb he brings to his smartass characters.

The actor, who turns 45 next week, certainly has the credentials for it: here is someone who left Harvard without graduating, and who announced his arrival on the biggest stage possible when he starred in and co-wrote the Oscar-winning screenplay for (1997) with childhood friend Ben Affleck.

Of , Damon says: "The fun of the book for me is watching a character - who's a lot smarter than I am - think his way out of this incredible predicament.

"Everything he does makes total sense. I wouldn't have known how to do it, but he basically solves the problems of food and water in a very technical way. It's all completely grounded in science, so it's very believable."

The character is "more resourceful" than he is, he adds.

"I kind of feel like if you left me in Hong Kong by myself, I might have a hard time - let alone on Mars. But our sense of humour is similar - I have a similar sense of humour to the Mark Watney character."

When it is pointed out that his film has been described as a cross between the space travel element of and the survival adventure in , he responds in wisecracking mode: "I think if we can just compare the movie to every Tom Hanks movie, that's good."

Unlike other sci-fi movies, though, Damon reckons is grounded in science and in reality. "That's Andy Weir's big premise: could an astronaut actually survive on Mars by himself under the right circumstances? It's really rooted in facts - whereas traditional science fiction is not," he says.

But before he can get a better read on his award chances after opens around the world this week, Damon has already gone back to work in his most popular role to date - as the super spy Jason Bourne.

Principal photography for the as-yet-untitled fifth Bourne film started in the Spanish city of Tenerife in early September. Slated also for a 2016 release, the film is Damon's first outing as Bourne in nearly a decade.

"I've always said I'd do another one if Paul Greengrass wanted to do it," he says of his director on (2004) and (2007).

"We made the last one in 2006, so it just took us nine years to decide to do it [again]. Once he said he wanted to do it, it was an immediate 'yes' from me. I love the character [Jason Bourne]; we just didn't really have anywhere to go with the story. We needed to wait for the world to change a little bit."

Would Damon be happy if Jason Bourne turns out to be the one character he's ultimately remembered for?

"Sure," he says. "I'm proud of those movies. They are hard work and really rewarding. And I love working with Paul. I'm happy if I'm remembered for that [series] more than or ."

The Martian opens October 1

RIDLEY SCOTT'S SCI-FI C.V.

While veteran British director Ridley Scott has made just a handful of science fiction features - technically four, including - over his four-decade career, he has managed to turn out two seminal classics and one major critical hit.

(1979)

The sci-fi film that launched Scott's career, made Sigourney Weaver an action heroine, and spawned an entire horror-in-outer-space tradition, this atmospheric classic begins with a spaceship crew picking up a lifeform and escalates to some hysterically intense moments, including that chest-bursting scene.

(1982)

A world-weary detective (Harrison Ford) comes out of retirement to hunt down murderous humanoids known as "replicants" (led by Rutger Hauer) in this dystopian neo-noir based on Philip K. Dick's 1968 novel and produced by Hong Kong tycoon Run Run Shaw.

(2012)

It started life as a much-anticipated prequel to but ends up a visually stunning 3D spectacle that hints at the cosmic history of humanity. Scott has since promised two or three more films, the last of which would link up to .