The Lonely - S1-E7
Other mistake: The supply crew arrives at the asteroid every 3 months, as established by the dialogue between Corry and the astronauts who bring him the female robot. However, Corry's narration reveals that he has been living with the robot for 11 months when the next supply ship arrives.
Answer: It's explained in the episode. The aliens are experimenting to see how humans react to various scenarios. This just happens to involve them using super strength.
Thanks. It's been a long time since I saw the episode so I forgot.