This is an Alien copycat that doesn't have scary monsters and the plot is mixed up. The astronauts inhabited by aliens for some reason are only inhabited part of the time. Why? I don't know and it doesn't matter. You know they are inhabited because they all of a sudden speak in a stupid computerized "scary" voice that isn't scary. The astronauts go places, but it doesn't matter. Then, they rip off the Terminator by having another alien that can kill them. By this time you are extremely bored and don't care. There are, however, lots of explosions. And there is the obligatory "man running away from large explosion just ahead of the leaping flames" scene. Yawn.