The adventures of Commander Zack Proton and the red giant / Anderson, Brian

Commander Zack Proton, mailman to the universe, opens the wrong door when he steps out for a break and falls out of his ship, only to be picked up by Omega Chimp, the last chimpanzee sent into space, and pitted in battle against the space giant Big Large.

After Commander Zack Proton opens the wrong door on his spaceship and finds himself floating in space, he's rescued by Omega Chimp and the two of them must save the spaceways from the space giant, Big Large.