I don't know, but suspect that the two biggest factors in the difference
between the 1955 calculations and the 1960's Apollo reality were the size
of the crew and the need to lift a sturdy spacecraft with a heat shield
off the Moon. And of course, the self-amplifying need for fuel when the
load is heavier: the heavier the load, the more fuel needed; the more fuel
carried, the larger the fuel tanks, making the rocket heavier, requiring
greater thrust, so heavier engines, requiring even more fuel... What's
the technical term for that kind of positive feedback?

-- Jeff, in Minneapolis

__________________
http://www.FreeMars.org/jeff/

"The other planets?
Well, they just happen to be there, but the point of rockets is to explore them!"
-- Kai Yeves