Shannon's alternative plan uses the current space shuttle fuel tank and solid-rocket boosters. The rocket would be carrying two new vehicles — a generic cargo container and the Orion capsule for astronauts currently being developed for Constellation. The new vehicles would have the capability to go to both the moon and the international space station.
This less expensive option would likely not be as powerful as Ares I and V, but would be simpler.
The cargo container would have to be developed. It, and the Orion capsule would sit on the external fuel tank like the shuttle does now. When the crew capsule flies, it would be inside the cargo carrier at the top, with an emergency escape system.
This is simply a rehash of the old Shuttle-C design, and it cannot put the necessary hardware into space for a greater US presence. As this article points out, all you could send to the Moon in terms of astronauts, with this system, is a mere two, limiting any lunar missions to simple "snatch and grab" missions like the original Apollo, and no possibility of an extended human presence on the Moon. Given this fact, we can unequivocally conclude that any manned missions to the Moon will not happen using this system. The moment its proposed, the modern heirs of the Roman Inquisition in Congress will kill it, by making the argument since the astronauts will "only" be doing the same things that they did during the Apollo era, there's no point in sending them, as the Apollo astronauts didn't discover anything "interesting." (Absolutely inaccurate as to what the Apollo program did and discovered, but you can bet money that's the argument the New Inquisitors will use, and they'll trumpet it at every opportunity.)
This, then, will lock us (if the program goes forward) into LEO only missions, but don't get your hopes up that even this program will fly. The New Inquisitors will not simply rest on their laurels, by any stretch of the imagination. The SDLV (Shuttle Derived Launch Vehicle) is being pitched as a "faster" and "cheaper" way for us to replace the space shuttle. The moment a delay or cost overrun appears (which it will, as they do with almost all things), the NIs will call for the death of the program as being an "expensive luxury we can no longer afford." They will cite whatever happens to be the cause du jour at the moment as a justification for their actions. The hue and cry will be to let the private sector (which is only focused on short term profits and not long term survival of the species) come up with a solution "some day," and without a "despicable" enemy like the USSR to worry about, the fact that the US has no ability to send humans into space will not seem to be a big deal. ("After all," they'll no doubt argue. "We've not been doing it for a couple of years now and the world hasn't ended so we don't need it." Nevermind that similar arguments were made about a large US military in the years leading up to any number of major wars.)
Equally as bad, in the unlikely event that the US does go to the SDLV and uses it to send humans into LEO, we will not make full use of what the design offers. NASA will continue to dump the External Tanks into the ocean, rather than parking them in orbit where they could be used at some point in the future to build an orbiting habitat or other structure.