Logician in space (5)
I believe the answer is:
spock
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">logician in space</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for spock that I've seen before include "Star Trek character" , "Star Trek Vulcan" , "In terms of childcare, a revolutionary" , "aka Leonard Nimoy" .)