Toronto, Canada | 

NASA may have grounded its space shuttles, but more Hollywood A-listers than ever are exploring the final frontier, with Natalie Portman launching one of two astronaut movie premieres at Toronto's film festival.

"Lucy in the Sky" opens with Portman drifting through space in her astronaut suit, begging her bosses for a few more moments to gaze at the cosmos before returning to the humdrum reality of life on Earth.

Eva Green's character in French movie "Proxima" also portrays the immense challenge of life as an astronaut -- an elite club, still more so for women -- but focuses on the grueling build-up to lift-off.

The actresses follow a string of marquee stars donning spacesuits in recent years including George Clooney and Sandra Bullock ("Gravity"), Matt Damon ("The Martian"), Matthew McConaughey ("Interstellar"), Ryan Gosling ("First Man") and Brad Pitt in the upcoming "Ad Astra."

So why does the astronaut continue to exert such a grip on our imaginations, half a century after the first Moon landings?

"It's such a childhood dream of course," Portman told AFP. "There's only like 80 people around right now who have been to space -- it's such a rare opportunity and rare personality and talent that achieves that."

Portman said going to space was "absolutely" a dream of hers growing up.

"It still is but I think I'm kind of past the point..." joked the 38-year-old. "I don't know -- maybe not. They say that space travel is going to be all privatized soon -- maybe we'll all get the chance!"

If she does, she will surely hope to fare better on return than her character in "Lucy in the Sky."

The Fox Searchlight film is loosely based on the real-life Lisa Nowak, who became a tabloid punchline following her arrest for attacking a love rival over a tawdry affair with a fellow astronaut soon after returning to Earth.

Headlines in 2007 focused on a bizarre -- and possibly unfounded -- report Nowak had worn adult diapers in her haste to drive from Texas to Florida to confront the other woman. Portman chose to focus on more philosophical elements.

"It's so rare to see a woman have an existential crisis on screen," she told AFP. "Having coming back from space and having seen the Earth as this inconsequential thing -- what does life on Earth mean after you’ve seen the whole galaxy?"

- 'Freeze... or boil to death' -

"Lucy in the Sky" received lukewarm reviews, although its creative use of shrinking aspect ratios as Lucy returns to a claustrophobic life on Earth -- from expansive widescreen in space to restrictive 4:3 ratio in suburban Texas -- was praised by some critics.

"What it's meant to do, without you noticing, is to pull you deeper into her state of mind," director Noah Hawley told AFP. 

"If I can do that, then when she makes those choices that you don't agree with, you're not going to judge her for it -- you're going to empathize with her."

More positive was the critics' response to "Proxima," shot on location including at the European Space Agency training facility in Germany.

Green plays a mother suffering conflicted feelings as she prepares for a space mission that will mean prolonged separation from her young daughter.

Again the fragility of the real-life people who go to space is foregrounded, with director Alice Winocour telling journalists she wanted to explore beyond the typical image of astronauts as "super-human."

Both Portman's and Green's characters are high-performing, perfectionist types who nonetheless struggle to deal with an experience so stressful it is impossible for most people to comprehend.

While the more routine launches of the past few decades have drawn a fraction of the interest of the Moon landings' heyday, romanticism and bravery remain tied to the concept of astronauts.

"There's no more dangerous pursuit than to literally get on a giant bomb, a rocket, and go to someplace with no air or water where you'll either freeze to death or boil to death in your suit if things go wrong," said Hawley.

In today's troubled times of divisive politics and the menace of terrorism, he said, space exploration retains its escapist lure on the big screen, if not in real life.

"The more of a mess that we make down here, the more we're going to romanticize and yearn for that ability to explore."

amz/ft