Jeff Foust has a link to a new report from the Congressional Budget Office. It doesn’t paint a pretty picture. I have to agree with “Red” in comments:

…if you consider that the goal of the Vision for Space Exploration was contributions to science, security, and economics in the context of strong commercial and international participations, none of these options will carry that out. They all involve Constellation/Ares, which is more or less the opposite of those goals. One aspect of this opposition is that the options that don’t postpone Constellation involve reducing science and aeronautics missions that actually do contribute to science, security, and economics (eg: using similar launchers and satellites to those used by defense and intelligence agencies)…

…With Science and Aeronautics already having taken huge reductions due to Shuttle and Constellation in recent years, and Obama’s push for Earth observations, fuel-efficient planes, NASA education, etc, I doubt that the science/aeronautics cut scenarios will happen. With such huge Federal debt/deficits and many agencies enjoying tons of money and sure to want to keep it that way, I doubt NASA will get the big budget boost scenario, either.

Basically, the numbers don’t work without major commercial participation, and getting control of out-of-control NASA areas like Constellation, Shuttle, and some larger science mission plans.

Emphasis mine. Unfortunately, there’s no sign that any of that is happening. The Ares zombie continues to plod forward at the cost of billions, and commercial participation remains minimal. And it’s unlikely to happen as long as becoming spacefaring remains politically unimportant, and in an environment in which pork dominates progress.

[Evening update]

Clark has another comment:

NASA needed innovative hardware architectures and mission designs to make Constellation “sustainable and affordable” as instructed in the VSE. Instead it chose Ares I and Orion and now all the budget scenarios are bad.

Funny, that.