Outer space, or at least the dream of it has never been as claustrophobic as it is in “Proxima,” the latest drama from Alice Winocour that finally gives Eva Green a role deserving of her as Sarah, an engineer who gets a shot at suiting up on an exploratory mission that will set up the first trip to Mars. It’s a day Sarah has waited her entire life for, having once put a lampshade over her head at eight to prepare for putting on a helmet, yet just as her imagination has allowed her to ascend to heights she never thought possible, the prospect of getting aboard the Soyuz 56 headed to the International Space Station plunges her into far darker areas of her psyche as she is about to spend a year away from her young daughter Stella (Zelie Boulant-Lemesle) and contends with the casual misogyny of a space program that’s long been dominated by men.

“Proxima” actually feels bigger by bringing its story to a human scale, even amidst a truly impressive recreation of the preparation and launch of the mission from Star City in Russia that one can only suspect seamlessly blends real footage into fiction, with Sarah and fellow crew Mike (Matt Dillon) and Anton (Aleksey Fateev) being put through the paces to test their stability and precision under pressure from running vertically, getting in and out of underwater pods and using mechanical arms. None of this proves to be a challenge for Sarah, nor does she seem fazed by Mike’s glib remarks about perhaps doing lighter prep work, but calls from her (supportive but weary) ex-husband (Lars Eidinger) as he takes care of Stella are bound to break her and she’s in an unenviable position of being caught between her own needs, her daughter’s needs and knowing a sacrifice of either is doing a disservice to all. Winocour and Jean-Stephane Bron’s meticulous script subtly layers the indignities that have bolstered Sarah’s resolve, from recalling when her mother told her to take the lampshade off as a child, saying such a career was impractical, to the hotel clerk at Star City paying her the backhanded compliment that the last woman to go had the dark side of the moon named in her honor, as well as all the ways in which she feels isolated that ultimately wear her down.

The inherent mystique that Green has primarily been asked to deploy as a means of seduction is shrewdly used here as an ineffable sense of purpose that eludes others who don’t have her passion, and while Sarah doesn’t care about what hardly anyone else thinks, her desperation for her daughter to understand her drive when she’s unfortunately too young to comprehend becomes truly heartbreaking. Green delivers a tinderbox of a performance as Sarah that is riveting to watch and Winocour, who has always been at her best when throwing every resource she’s had at her disposal to bring what’s inside her character’s out from intuitive camerawork to inspired musical choices – here, she has a brilliant score from Ryuchi Sakamoto, fluctuating between earthy instrumentation and otherworldly sounds you can’t quite place that compliments a story that truly is told largely on Sarah’s face – has found the best vessel yet in both narrative and lead actor for one of her experiential character studies. While everywhere Sarah looks there are reminders of what’s keeping her tethered to the earth, looking at her in “Proxima” reminds of the heavens above.

“Proxima” screens at the Toronto Film Festival on September 7th at 6:15 pm at the Winter Garden Theater, September 8th at the Scotiabank at 1:45 pm and September 13th at the TIFF Bell Lightbox at 12:15 pm.