Space travel
The book involves an obvious use of space imagery in its science-fiction. The purpose of this imagery is up for debate, but its effect is clearly to broaden the imaginative domain of the story. This allows for interesting thought experiments in the fiction, because it maintains the veil of reality (who knows what space might contain?) but it stretches the scope of reality to contain sci-fi ideas like bio-technological life forms. The space itself is a symbol for the breadth of real space, because after all, the universe is unimaginably large.
Horror and death
This could be a nice space travel book, like a diary about how cool and fun it is to travel through space. But that's not what the book offers. They're not just vacationing in space; they're trying to figure out what happened to a missing ship (a scary proposition). Not only this, when they finally arrive, they find the horror is even more pronounced than they ever imagined. There is an alternative form of life, one that seems less sensitive to death because it is biological and technological, and it seems to be based on a strange, mystical kind of technology that undermines their sense of "normal reality." The domain of Regis III is the domain of horror and death, and they find a lot of dead bodies.
Regis III
The imagery of Regis III is similar and different from earthly imagery. Regis III also has broad landscapes that are perhaps beautiful, except that the life that covers them is inorganic and confusing to Rohan. He wants to find survivors, but Regis is not the planet for survivors. He finds dead bodies again and again, and Horpach wants to abandon the mission and save their lives, but the imagery of Regis III makes Rohan desperate for some kind of hope, so he fights to save even just one person.
Imagination and the sublime
By stretching the concept of "normal life" to include space travel, the novelist creates a whole new domain for himself to explore. Who's to say that in the far corners of space, life isn't even more strange and sublime than life on earth? The creative use of imagination actually provides two kinds of imagery. There is the sublimeness of the sci-fi world, and there is the suggestion that normal life is not less sublime than the science fiction. The biological technology of life on Regis III is a reminder that technically, life on earth is unexplainable too, and somewhat technological in the same strange mysterious ways that the imaginary life on Regis III is.
