The Eternaut, Hardcover/Hector German Oesterheld

This originally appeared as weekly installments from 1957-59. Juan Salvo, the inimitable protagonist, along with his friend Professor Favalli and the tenacious metal-worker Franco, face what appears to be a nuclear accident, but quickly turns out to be something much bigger than they had imagined. Cold War tensions, aliens of all sizes, space--and time travel--this one has it all.