Actually, you can do manned Mars or CAPS using as little as 20 ton modules, same payload as is used for defense and commercial purposes. We'll be seeing Russia and China, along with maybe the EU and Japan, using this route just a few years from now. (You can go over to the Encyclopedia Astronautica for previous architectures, or go to Portree's site. I don't know why Russia is offering tourists lunar orbit with a Soyuz and a Proton, when one Proton can do the job. Perhaps its because a visit to the station is also included in the deal.)

As far as the more capable clustered Atlas's and Delta's go, you have to remember that the system architects in both Houston and Langley were flanked by ATK. It was a brilliant move on ATK's part, but as a result of their flanking movement, their architecture does not allow for CAPS. Since the nation is opposed to paying for manned Mars flight now, without CAPS both their achitecture and Bush Jr's vision are equally doomed. No bucks, no Buck Rogers. And then there's the possible problem with the ozone...

Baring some kind of miraculous change, there's little to do now but sit back and watch it all go down.

Its depressing as hell.