The 90 day archietecture for Bush Snr's vision was based on the use of the shuttle, and the costs were astonomical, to use the appropriate word. Griffin was around for that exercise and knows what a dog the shuttle is.

If you remember, years ago in an interview with John McLaughlin, Goldin expressed his thinking that after the new commercial launchers (including the RLV) were developed, the shuttle could be converted into a shuttle derived heafvy lifter for a manned flight to Mars before the year 2020.

ATK obviously wanted some of their engineers to continue to think along those lines, and we now have a picture of their proposed lunar insertion stage available:

http://www.safesimplesoon.com/charts-lg.htm#reliability

Undoubtedly they also have rough outlines of their Mars achitecture ( old copies may be out on the net somewhee), but they are not making these available right now. The issue right now is CAPS, and getting it passed.

Their architecture is very good engineering. The only problem is the possibilty that solids are helping the freon reaction in the creation of the ozone holes, and these holes are causing very serious problems: Skin cancers, deaths from malignancies, unknown effects on climate, etc....

The B team must be working right now with the EELV manufacturers, who are coming up with their own architectures and costs... Griffin is likely supporting this B team planning effort, which makes it all sweet in terms of Congressional action: no lobbying after the two plans are proposed, just a plain technical-cost disccussion...