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Manfred Clymes and Nathan Kline co-wrote an essay called "Cyborgs and Space" and published it in
Astronautics in 1960. Here's the subtitle-ish lead: "Altering man's bodily functions to meet the requirements of extraterrestrial environments would be more logical than providing an earthly environment for him in space... Artifact-organism systems would extend man's unconscious, self-regulatory controls."
Here is a link to the article.