Actress Natalie Portman said it was "absolutely" a dream of hers growing up to be an astronaut. — AFP Photo

TORONTO — 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 said. "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 privatised 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 said. "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?" — AFP