Not space travel but in Well's "The Invisible Man" the invisible man is totally transparent which would limit the story a bit since it is light impinging on the retina that allows us to see. So either the invisible man is blind or others would see a pair of eyes floating about with no body. Of course Well's had his 'cavorite' to screen a ship from gravity too. At least Verne tried to keep within known science in his stories. Still Mr. Well's books are fun to read even with the errors.