Sci-fi 'Moon' explores loneliness, clone-liness

"Moon" might be a once-in-a-lifetime experience for fans of Sam Rockwell. Will there ever be more of him in one movie than there is here?

This is partly a matter of time (he's in the whole movie). But it's also a matter of volume: There's more than one of him. Rockwell in duplicate is the most interesting thing about "Moon." Generically, a place; specifically, it's where astronaut Sam Bell (Rockwell) is finishing a three-year stint mining a new energy source for Earth.

Sam lives in a cavernous space station. He speaks to his wife and daughter via video chat. He heads out in a lunar vehicle to do repair work. He makes small talk with his Gerty 3000 Robotic Assist (Kevin Spacey), which cuts his hair, has emoticons for facial expressions and holds his conversations in a voice not unlike that other famous talking movie supercomputer's, the HAL 9000.

Sam is injured on one of his repair missions. When he awakens, he finds he's not alone. Another Sam is exercising in the rec room. The original Sam is delirious from the accident and distrustful of his clone. From where has this sterner, more virile Sam come?

Written and directed by the first-time director Duncan Jones, "Moon" devotes itself to the mystery of the multiplying Sams.

Since we spend so much time in a kind of "2001"-meets-"Solaris" scenario, one with its strains of Ray Bradbury, we're invited to notice how little vision or scope or psychological texture there is in "Moon."

As Sam's situation turns strange, despairing and eventually sinister, the movie's initially welcome modesty becomes a limitation. Nothing here is as interesting as it seems.