Astronaut Sam Bell (Sam Rockwell) works in isolation in Duncan Jones' film Moon. (Mongrel Media)

Sam Bell (Sam Rockwell) is the man on the moon, and it turns out the gig is not the all-cheese, all-the-time funfest you might think. He's been up there for nearly three years, a drone for a Korean-American corporation that mines "safe, clean energy" by dredging up the dark side for Helium-3. The machines do most of the work, but flesh-and-blood Sam is there on the off chance that something derails. Hence, he spends a lot of time inside the station, a white-walled, gleaming nod to Stanley Kubrick's 2001.

Moon is good, old-fashioned sci-fi of a literary sort, short on the kind of showy F/X that pad most movies in the genre.

But as Sam nears the end of his contract (and grows an end-is-nigh beard), human detritus encroaches on the pristine environment. He stops hanging up his jumpsuits, and spends his spare time building a large model of a town and gazing at the pictures of his wife and child haphazardly Scotch-taped to the white walls. His only companion is Gerty, a hovering computer with a skin-crawlingly gentle voice (Kevin Spacey, whose innate vocal creepiness is put to good use). Whether that lulling voice signals a benign or malevolent force is determined much later.

Director Duncan Jones —who also wrote the story that inspired the script — creates a consistently troubling world; the desolation and loneliness of the place are writ large on Sam's face. Rockwell is a strange actor with a kind of jittery, room-filling quirkiness that belies his leading man looks. He generally chooses oddball roles, and charges at them. As game show host Chuck Barris in Confessions of a Dangerous Mind (2002) or an academic in Frost/Nixon (2008), he's committed and forceful, like a less pretentious Christian Bale, or a more functional Crispin Glover.

But what Jones pulls out of Rockwell is something the actor often damps down: likeability. Sam is a gentle guy, yearning for home — a slightly comic everyman. Even Gerty seems to like him, responding to his chatter with a little yellow smiley-face icon that can turn sad or confused, and is as close to human response as Sam experiences up there.

Sam longs to return to his family and life on Earth. (Sony Pictures Classics)

Sam takes his job seriously, even though it's the drudgework of a glorified security guard. A video message shows his wife prompting their toddler daughter: "Say astronaut! Daddy's an astronaut!" A flicker across Rockwell's face expresses how clearly he knows that his reality is bound up in the romance of the word "astronaut."

When Sam puts on his suit and goes outside one day, Moon takes a turn. Though many reviews have revealed the film's plot-hinging twist, this one won't — the jolt is half the fun. But suffice to say that something happens to shake the foundation of Sam's being, bringing into question what, if anything, separates man and machine. In other words, this is good, old-fashioned sci-fi of a literary sort, short on the kind of showy F/X – no Terminator Salvation rock 'n' roll big bang here – that pad most movies in the genre these days. Moon has a kind of lo-fi simplicity that feels like a salve in the explosive summer season, quietly posing a series of speculative "what-ifs?"

Jones creates a great, melancholic atmosphere, and it shouldn't surprise anyone to find out he's the son of David Bowie. Moon is his first feature, and at times, the story gets away from him; there's a looseness to the pacing that a more seasoned director might have resolved. On the other hand, that slightly unfocused, ephemeral quality suits the material. And Jones has found a great collaborator in Rockwell, essentially the star of a 94-minute one-man play. Moon is a nice little scoff at the disposability of workers; it's the ultimate outsourcing movie, using the future to expose our present-day cruelties.

Moon opens July 3 in Toronto, Vancouver and Montreal, and July 10 in Victoria, Calgary, Edmonton, Winnipeg and Halifax.

Katrina Onstad is the film columnist for CBCNews.ca.