Interesting. The timeframes seem outlandish, but then so is Moore's Law. Arguably what has held us back from exploiting space (apart from the fact the the Apollo program cost nearly 4% of GDP) is our problem with risk. The number of fatalities of aviation pioneers prior to WW1 was mind boggling, but we had a different attitude towards risk and mortality in those days. As life expectancies rise, so does our aversion to risky behavior. But the real problem is this; just as people become risk averse, so do Governments carrying 'image' (think Challenger) and Corporations carrying insurance. Privately funded institutions which fund their own risk don't have those constraints. And there will be enough 22 year old hot heads ready to ride on top of a rocket to fame or oblivion. Possibly not enough with a good educaiton, however, to keep us ahead of the Chinese efforts in this direction.