The accepted father of popular science fiction was?

Depending on your precise definition of "popular science fiction" and "accepted", that would most likely be either Jules Verne or Isaac Asimov. Just watch the protests that result to see why this question has no "answer"!

Mary Shelley has been given that distinction for her novel 'Frankenstein'

Hugo Gernsburg

John Campbell

Cyrano Deburgerac for his travels to the moon

Daneil Defoe

Johnathan Swift for Gulliver's Travels

the myths of Daedalus can be termed gadgetry Science Fiction and go all the way back to the bronze age.