What does "unconscious death urges" and "schizophrenic drive toward isolation" mean?
Will he (a future spaceman) need bones of steel and powerful muscles to resist rocket thrust，the lungs of a glass blower，a mighty heart， the aplomb of an acrobat，unconscious death urges，or a schizophrenic drive toward isolation？
I suppose that "unconscious death urges" means that he has a strong wish to die even though he doesn't realize it, and "a schizophrenic drive toward isolation" means that he enjoys being alone very much.
It seems that it makes sense if a future spaceman enjoys being alone, but I don't understand why a future spaceman need to have a strong wish to die.
How do you think about it?
Thank you!Popular ideas of a spaceman tend to be weird composites of comic-book fiction and fact．