I just found that NASA's ESAS (Exploration System's Architecture Study) has been published as of December 27th, 2005. This is a detailed look at all of the CEV (Crew Exploration Vehicle) architecture including Shuttle Derived Systems. It looks at many ways to achieve ISS Assured Crew Return, lunar landings and possible future Mars missions. All 752 pages are availble through SpaceRef.com as pdf files:
Scroll down and you will see an index of all 17 sections of this report. Anyone curious about NASA's plans for future spaceflight would be advised to look this report over...
