An astronaut who is just over six months into a solo mission to investigate a mysterious galactic phenomenon, Jakub (a tortured, reined-in performance from Adam Sandler) is ill-placed to deal with the breakdown of his marriage to his pregnant wife, Lenka (Carey Mulligan), left behind on Earth. Fortunately, an alien spider with the voice of Paul Dano and all the wisdom of the universe has stowed away on the vessel and offers Jakub ad hoc therapy sessions.
Jakub and his (possibly imaginary) emotional support arachnid drift aimlessly towards some kind of nebulous insight, accompanied by a score that sounds like the kind of formless ambient wafting that gets piped into a floatation tank. Spaceman is a fascinatingly odd premise let down by its drab, dispiritingly inert execution.