Which "Old Sci-Fi Hero" Should Frank Miller Revitalize?

Frank Miller has been talking with Deborah Del Prete, his Spirit producer, about some possible follow-up movie projects, one of which might be a remake of an old sci-fi property.

"We're thinking about revitalizing an old sci-fi hero," Del Prete told Collider.

Unfortunately not much more was revealed. Last May it was rumored before it was quickly debunked that Miller would be doing a Buck Rogers reboot.I know its not a lot of information to go off of, but I'm curious – what movie do you think it could be? And what "Old Sci-Fi Hero" would you like to see Frank Miller revitalize?