Hal Clement (Harry C. Stubbs)A quiet and underrated master of "hard science" fiction who, among other things, foresaw integrated circuits back in the 1940s.
I gotta tell ya, Mission of Gravity is one of SF's classics. I'm not sure I want to write it; I don't think Clement's human beings were truly human. But Mesklin was a cool place, and Barlennan a neat character. Therefore I am happy to be Hal Clement.