> in a more risk-reducing fashion, with a smaller section being built top-to-bottom to demonstrate its viability? My guess would be the time. If this would be

> in a more risk-reducing fashion, with a smaller section being built top-to-bottom to demonstrate its viability? My guess would be the time. If this would be built in 3-5 years, then with a demonstrator it would take 5 to 10 years to complete. Also - not enough (heh) money constraints.