<PERSON>
A deadbeat dad joins the Russian space program so that he can come back a hero and actually *be* something to the son he abandoned. He comes back with an alien inside him that comes out at night and eats the most vile of prisoners.
This is a pretty forceful statement about the male psyche and the violence wrought upon it when it becomes part of anything that the military has an interest in. Even the most un-"heroic" actions, like going to space ("sitting in a tin can", as one character refers to it) are inseparable from the military's goals of control through deadly weaponry, and give support to the deaths of people. 999
This is <PERSON>'s (the woman scientist) philosophical opposition: no matter how vile the criminals are, they are still people.
And so, on the level of the individual male, the honor he hopes to gain in his child's eyes by being a hero (or maybe the ability to provide that comes with being a national hero) is revealed to be useless, and a deadly detour from actually being, you know, anywhere physically near the child to do anything for them. The man wants his son, and is ashamed of how the military turned him into a monster and made the world that less safe for all children.
The alien feeds on cortisol, produced when humans are afraid. The military feeds on fear, and puts this alien into every man who signs up to be any kind of soldier. 295