I’ve never been particularly envious of astronauts. I enjoy Earthly comforts like solid food, the internet, a few square feet of space to myself and good company. Early on in I.S.S, astronaut Kira Foster (Ariana DeBose), newly aboard the titular space station, isn’t as thrilled as she should be by the view of the Pale Blue Dot. She’s unsettled by her prickly Russian colleagues, her claustrophobic quarters and the numbness of the void. This is not a film about the beauty of space.

I.S.S features a cast of six. There’s the American trio: Foster, veteran astronaut Christian and mission commander Gordon, as well as the Russian contingent: Alexey, Nicholai and Weronika. When nuclear war breaks out on Earth, both teams receive the same orders: seize control of the I.S.S.

Thankfully, director Gabriela Cowperthwaite doesn’t take the easy route by splitting their loyalties cleanly down the middle. Gordon and Weronika are an item (which seems like it would break some sort of protocol, but I won’t get in the way of love), and Christian’s mixed allegiances imbalance the scales even further. I.S.S is less about nationalism than it is one about pure survival instinct, by any means necessary. Indeed, the nationalist dimension of the ensuing conflict is constantly juxtaposed with hauntingly beautiful shots of an Earth ravaged by nuclear fire. The I.S.S would seem to be insulated from the political struggles of the world below, but can’t escape the gravity of human nature.

There are only a few outbreaks of actual violence over the course of I.S.S’s lean 95-minute runtime, but these few moments are the highlights of the film. It is somehow astonishing to witness these astronauts, seemingly people of supreme rationality, brutalize each other with whatever makeshift weapons they can find. The violence recalls 2001: A Space Odyssey, where early humans beat each other to death with bones on their way to becoming a spacefaring civilization. I.S.S isn’t action or horror by any means, but these “fight scenes,” if you could call them that, hit you with a visual force that is surprising, given the absence of gravity. I.S.S shows us how there are no heroes or villains in this sort of conflict–just the living and the dead. When the credits roll, you aren’t sure who’s better off.

The result is a simple thriller that succeeds at creating tension, even if its characters float a little aimlessly. I.S.S isn’t a sci-fi masterpiece, but it does show us what happens to warm bodies in the cold vacuum of space.