"Charles Talleyrand" wrote in message ...
I'm trying to imgaine cheap space flight. I'd also like to see it
sooner rather than later. Given this I believe we are limited to
chemical rockets.

If you are talking about cheap, but politically unrealistic
spaceflight, I don't think anything could beat Orion. More politically
plausible would be NTR , I think still cheaper then chemical (without
development cost).