New Ventures Society
Hotel Ad Astra
Initial $10 billion
expansion $20,000 billion
upgrade $6,000 billion
This is a bit vague but it is the effort to develop space beyond the first true spaceships. It would involve building a manned space station with artificial gravity provided by centrifugal forces and a permanent population. Each segment would be designed and manufactured on Earth and lofted into space to be assembled in Low Earth Orbit. This would provide the way station to venture to the Moon and develop a permanent colony. Lunar resources both ceramic and metallic would then be used to construct the initial space habitats because of lower costs to lift from the weaker gravity.
In spite of the early beliefs that zero gravity would be the ideal geriatric condition, man needs gravity. So the hotel will rotate at no more than 1 RPM - thus it needs to be big to generate 1 G. In fact we should probably go out to 1.5 G because mouse studies demonstrate that individuals growing up in 1.25 G were much stronger and healthier than controls.
So we start by designing a workable space station. Bigger than the one envisioned by Wiley Ley, more on the ideas of Gerard O'Neil. With radiation shelters, massive "fuel" storage (water), power plants and construction facilities in addition to the requisite Hotel.
And the rockets for the next step shift from the massive thrust needed to get off the Earth to vessels more conservative of reaction mass using mass drivers and ion motors. Slow and steady continuous drives.