Joe Penna’s Stowaway is set in a near-future in which manned missions to Mars are a regular, but hardly risk-free, occurrence. On the latest three-person mission to Mars, ship’s commander Marina (Toni Colette), medical researcher Zoe (Anna Kendrick), and biologist David (Daniel Dae Kim) discover a titular stowaway Michael (Shamier Anderson), a space company engineer who is injured and trapped on board the ship during its launch. A long-term problem, the ship only being stocked for a crew of three, becomes a more immediate one as Michael’s accident prior to launch has damaged the life support system, causing their oxygen supplies to rapidly deteriorate. The crew is faced with a grim decision in order to save their mission and hopefully themselves.

Penna’s film is a relatively simple conceit, benefitting from the inherent tension of the crew trapped in an inescapable environment with dwindling good options. The performances are passable, adequately portraying the swings between panic and reason that their intractable situation brings. Impressively, Penna takes the time to linger in some of the quieter moments of reflection, taking a few sidetracks off the standard space disaster path of swiftly moving from alarm blaring crisis to crisis.