Alice Winocour’s Proxima opens not with a launch sequence but with a medical exam. Sarah, a French astronaut played by Eva Green, is being measured, assessed, certified — her body the instrument of a system that has decided she is ready. What the system does not measure is what she is leaving behind, and that gap is where the film lives for the next 107 minutes.

Sarah has been selected for a year-long mission to the International Space Station. The preparation, which Winocour films at the European Astronaut Centre in Cologne with a near-documentary precision, is months of training alongside American colleague Mike Shannon, played with a studied lack of self-awareness by Matt Dillon. What keeps interrupting the protocol is Stella, Sarah’s seven-year-old daughter, who lives with her ex-partner Thomas (Lars Eidinger) and who is slowly working out what her mother’s departure actually means.

Green delivers a performance of extraordinary containment. She plays a woman who has absorbed the institutional logic — show no weakness, stay functional, separate attachment from competence — without quite succeeding at it. The cracks in the professional surface appear in the smallest gestures: a pause before a goodbye call, a grip held a moment too long. Zélie Boulant, as Stella, answers with an equally precise child’s intelligence, registering every micro-shift in her mother’s emotional temperature. Their scenes together are the film’s center of gravity.

Winocour shoots the gap between these two worlds with controlled elegance. Training facilities render in a cool, fluorescent palette; scenes with Stella find a warmer, softer light. The editing keeps these registers distinct, which makes the moments when they collide — when the professional and the maternal demand the same room — carry real pressure.

Sandra Hüller appears briefly but pointedly as a German colleague who has already made the adjustment Sarah is still resisting. Matt Dillon’s Mike is a subtler achievement: a man so accustomed to the logic of institutional separation that he has lost the ability to recognize when someone else hasn’t completed that transaction.

The film occasionally tests patience. Winocour favors observation over narrative momentum, and there are stretches in the second act where the contemplative register doesn’t generate forward pull. The final sequence — Stella watching the launch — walks a careful line between earned feeling and sentiment, and largely holds it.

Proxima is the argument that space cinema has been telling the wrong story for sixty years. It is not about leaving Earth. It is about what you leave behind when you do. Alice Winocour and Eva Green make that argument with discipline and precision — and without the consolation of a tidy resolution. The system, after all, was not designed to produce one.