FYI: Drexler article on Mars

Still fighting the Martians, eh, Mike. Yeah. You'd think I could find a better hobby. Well, I want to go to Mars,
too, but I think that there is a better way of doing it. A dumbell
holding about 150 people is a good first step for a "humans to Mars"
mission. As big a "orbital infrastructure" person as I am, even I wouldn't insist that a 150 person dumbbell was needed for a first step (although that would certainly be preferable). But I would say that massive settlement of Mars had better be taking into consideration transportation systems on this scale, and a hundred other things which will mass 10 times more. And that High Frontier can help. Some Mars advocates correctly point out that High Frontier is not needed to mount Mars Direct, and then try to leave you with the impression that Mars Direct will somehow lead to massive settlement of Mars.