Nietzsche wasn't nearly as miopic as Hitler and he had a fallout with Wagner. Nihilism really focuses on how what has been created for mankind to exist (particularly morals) are constructs, and we should realize that what
limits us is our built-in preconceptions that have been force-fed to us. The concept of evolution, for Nietzsche, is a highly individualized experience that is as free from man-made constructs as possible. It is no wonder that the existentialists were highly influenced by him. The Superman still does not exist, and in this post-modern era it is looking less and less likely that he can due to the totality of hyperreality.
The concept of space travel and self-improvement by learning, to me, do not seem very strong in their evolutionary goals from a nihilistic standpoint because they don't do for the rise of the individual. Self-improvement by learning is vague, because I think most learning is simply the socialization process... but, if by learning, you mean creating and breaking down the imposed moral boundaries that have been created for us - then you may be on to something.
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Janet forgets to sign off
-Will