Hi, Don.

You're probably much more up to date with the topic than I am, so I'm not about to argue any points, but:

It would be irrational to fund the development of a method of transport that's neither cost effective nor of optimum service efficiency for the tasks to be undertaken during the projected lifetime of that transport - which begs the questions:

1. Where is the NASA space program heading?
2. (and 3!) What kind of transport will most effectively meet the demands of that program. And why?

"Time is what prevents everything from happening at once" - John Wheeler