Quick Shiny Rocket Follow Up

The cheapest option (cheaper than probably all of the options I discussed earlier), would have been to use the Delta IV Heavy as the Crew Launch Vehicle and to use the Shuttle-C style cargo lifter.  Shuttle-C removes the space shuttle orbiter from the shuttle stack and replaces it with a big cargo carrier.  Since the shuttle itself weighs about 100 tons, the Shuttle-C idea can place some major weight into orbit.

The Shuttle-C either throws away three SSMEs per launch (very expensive) or recovers them using a too-be-developed mechanism (meaning larger start-up costs, but lower operational costs).