G’day D&S,
If you re-read the sentence in your post that begins “This orientation…….” I think you will find most of the answers you want. After the SS has performed the roll maneuver it is effectively on the upside of a loop, a very large loop, that eventually puts it into orbit. As the statement says the crew have a good visual reference and a positive ‘g’ loading. Much more comfortable than having to do an outside loop.
All orbital launchers gain considerable advantage, be it payload or increased fuel load, by launching to the east, in the direction of the earth’s rotation, and as close to the equator as possible. As an aside even jet airliners gain a small advantage if they happen to flying east at low latitudes. The speed of the airliner around 500kts plus the rotational speed of the earth at the equator 1000kts gives a velocity of 1500kts. This to a small degree counters the effect of gravity so that although the mass of the airliner is unchanged the weight is effectively reduced by about 1%. There is a measurable fuel saving associated with this. Lookout if you happen to be flying west. It is all explained in CH13 of the latest edition “Mechanics of Flight” by Kermode.
Mike Echo has a good point about the economics of rebuilding the launch site.
Regards.
