Pic one looked at different mixture ratios in the engines and their effect on vehicle design...
Pic two is a closer look at the pressure-fed liquid booster design...
Pic three is a cutaway drawing of the vehicle core with the 12 SRMs clustered around it. Part of this study looked at different methods of attaching the SRMs to the core. It was found that with the LOX tank forward, placing the main thrust force transfer structures from the SRMs into the core vehicle at the forward skirt would lighten the structure significantly, since the LOX tank had to be heavier to handle the loads anyway, and the LH2 tank would be in tension and therefore had the same loads as the core vehicle alone (no boosters). The forward skirt had to be significantly stronger (and therefore heavier) but it saved considerable extra weight in the hydrogen tank walls if they didn't have to support the extra forces of the SRMs transferring their thrust into the aft end of the vehicle and through the hydrogen tank walls. This idea would be carried forward on the space shuttle, which transfers the thrust forces of the SRB's through the FORWARD attach points into the intertank beam, which supports the heavy LO2 tank above it. The lighter LH2 tank below the intertank beam remains in tension until SRB burnout and SRB jettison, when it comes under compression loads from the SSME thrust, but by this time it's half empty (at least) and the loads are far more manageable. (it's a little more complicated than this, but it makes the point). To negate the extra weight added to the forward skirt of the heavier beefed up booster-thrust absorbing version, a second lightweight version was proposed for when the vehicle flew alone without boosters...
Pic four is an enlargement of the back half of the drawing...
Pic five is an enlargement of the fwd half of the drawing...
More to come! OL JR
