Despite the obvious focal point of the journey, literally blasting off into space for a year-long mission on the International Space Station, “Proxima” is mostly invested in the minutiae of Sarah’s professional path and the painful intersections it has with her family life. Green, so often cast as the icy femme fatale, is devastatingly open-hearted as Sarah, believably juggling the unique pressures of both parts of her life. She is also her young daughter Stella’s (a remarkably assured Zélie Boulant) primary caretaker, which further complicates the price of her ambitions: who will be there for her when she takes off for an entire year? Her ex (Lars Eidinger), with whom she seems to maintain a tenuous peace, is reticent for the gig, though he eventually gives in.

It’s the kind of worrying trade-off so many single parents, often mothers, have to face in less grandiose terms. Sarah, at least literally, can’t have it all, not at one time, not in one place, not on this planet, and while Winocour is often bluntly literal with her thematic statements — look out for an actual wall that separates Sarah and Stella late in the film — she’s still mining very real problems for them. Elementary school-aged Stella is more in tune with the dangers of the mission than one might expect, asking Sarah probing questions and consuming a steady clip of information about space travel on her own time. As Sarah struggles to acclimate to her training and team, Stella finds her new life with her father to be similarly discomfiting. The pair remain deeply bonded throughout the film, two sides of the same coin. Still, as Sarah’s quest gets closer to its ultimate goal, her bond with Stella suffers, especially as the kid grows closer with both her dad and Sandra Hüller, who appears throughout the film as a soothing administrator tasked with assisting families through the weirdness of a space trip.

Sarah’s quest is further complicated by the fact that she’s the lone female member of the crew. Soon, she’s saddled with a charismatic but pompous leader in Mike (Matt Dillon), who uses Sarah’s official introduction as an excuse to unfurl a wide variety of stereotypical thoughts on both women and French people. Mike initially becomes less of an ally with each subsequent interaction, only further highlighting the latent sexism she faces in her work, though he eventually comes to see Sarah as (gasp!) a very real person worthy of respect. And does she ever deserve it. Winocour plunges Sarah (and the audience) into the repetitive and sometimes scary training she must undergo immediately, from navigating through a smoke-filmed room to running up walls to pushing through tense underwater missions. Even after she makes the cut for the mission, things only become more intense, and the physical and emotional toll is great, made worse by the fact that Sarah feels more compelled to prove herself than any of her male counterparts.

The result is an immersive, often ponderous exploration of what it means to become, as Sarah puts it, “a space person.” While less bombastic than fare like “Interstellar” and certainly less effects-driven than “Gravity,” “Proxima” is catnip for anyone obsessed with process, with people going beyond their boundaries, with training montages that often end in tears. The drama ramps up to a satisfying final act, and while Winocour and Green don’t splash out on surprises, the emotional value of “Proxima” soars high above the fray.

Grade: B

Vertical Entertainment will release “Proxima” on VOD and digital platforms on Friday, November 6. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.