Moon is a British Science fiction movie that was released in 2009 starring Sam Rockwell. The movie was directed by Duncan Jones.
70% of the planet's energy needs are now being taken care of by Helium 3 (HE3), which is being harvested on the dark side of the moon. Sam Rockwell (a lunar miner) is currently charged with harvesting HE3, he is coming to the end of his 3 year posting and is set to return to Earth to reunite with his wife and daughter.
But when Sam's health takes a turn for the worse, he begins to hallucinate a younger version of himself also being present.
With the aid of his AI helper GERTY (voiced by Kevin Spacey), he tries to solve the mystery before the incoming Lunar Industries "rescue" team arrives.