Loretta Hidalgo Whitesides has an article in Wired on why NASA is building the Ares Rockets instead of using the Atlas or Delta rockets that are already built. Her arguments are basically:
- The Orion Capsule is to big
- Man rated capsules need triple redundancy and it would be to hard to retrofit those rockets
With all due respect, this is a good example of "begging the question". They design the Orion around the capability the wanted the rockets to have, so of course it is to big. We could have used a smaller capsule and done multiple launches (which they will have to do anyway for a Mars or Asteroid mission). And nobody is upset that we are building a more capable rocket, but that we are building a new rocket. It cost a fortune. You can't tell me that retrofitting an existing, working rocket is more expensive than building two new rockets from scratch.
There is the other point that Deltas and Atlases would provide access to space during the "gap" planned after the shuttle retires in 2010. The Ares 1 will not be ready until 2015 (if then).
Now whether we have come to far to turn around I don't know, but there is an Turkish saying:
"No matter how far you have gone on the wrong road, turn back."