Despite the Space Shuttle is the only ready available and flying US spacecraft it will be, quite sure, retired at the end of 2010 and never replaced by (now deleted) and very expensive Constellation program that, as admitted, last year, by NASA, would be not able to carry a crew to the ISS before EIGHT-TEN YEARS from now with an R&D-only costs around $50 billion to which we must add the costs of the Orion/Ares-1 hardware that could be in the range of at least $1 billion per EACH launch (excluding the fixed annual costs) that, assuming it was REALLY able to fly, since, in my opinion, deleting Constellation, the President Obama has made a big gift to NASA avoiding a giant humiliation the day that would become clear that the Ares-1 was badly designed and not able to fly, as clearly demonstrated by the Ares 1-X test, then it was DEAD before born!
The only advantage of the Orion (vs. the Shuttle or the proposed "commercial" crew capsules) is that it was designed to accomplish a lunar mission, but, to do that, NASA should spend a further $50 billion for R&D only to develop the Ares-5, the EDS and the Altair and spend (at least) $100 billion (+ costs overruns) in lunar hardware and fixed costs to accomplish less than a dozen lunar missions in five years from 2025, or later!
The alternative chosen to replace the retired Shuttles and the stellar expensive Constellation should be the "commercial space" that, unfortunately, will have a price-per-ton to ISS up to FIVE TIMES HIGHER than the Space Shuttle and could need FOUR-SIX YEARS from now to accomplish its first mission to the ISS, while, its crew launch version, should cost (at least) $6 billion only for R&D (+ cost overruns) and excluding the hardware costs (that should be in the range of, at least, $300-400 million per launch, for the most optimistic evaluations) to accomplish its first manned mission to the ISS within SIX YEARS from now (+ delays) and with a completely unknow and unpredictable safety and reliability compared with past and today's vehicles like the Apollo, Shuttle and Soyuz, also, the "new.space" crew vehicles can't return from the Moon, so, they can't be used for lunar missions that need a new and specific vehicle.
But, if NASA and the new US administration REALLY want to embrace the "commercial space" why don't ADOPT ENTIRELY the capitalist rules, buying only what is really available on the market at the best price, no matter, if the "best buy" is american, european, russian, chinese, indian or japanese, like, after all, we already do with much more important and strategic products like the computers, cellphones, etc. that, today, are manufactured at low prices ONLY in Asia and, especially, in China.
Well, if the, rational and pragmatic, "commercial" and "capitalist" choice is made in its entirely, the inevitable decision to replace the Space Shuttle can't be to adopt the (very long and expensive) Constellation hardware, nor the (long and not so much cheaper) "new.space" vehicles, but MUST be to BUY the (ready available, safe, reliable, 1700+ successfully launched and very cheap) Soyuz rocket/capsule (and its cargo version Progress) then launch them from KSC as will soon happen with ESA from Kourou in French Guiana (as you can read in this news France has ordered 14 Soyuz carrier rockets from Russia costing some $1 billion).
Despite at first glance the idea may sound crazy nearly ALL advantages and numbers are in FAVOUR of this solution, since, if NASA buys the Soyuz and Progress and launch them from KSC, they will SAVE the $50 billion of the Constellation program (for the ISS-only version) the $3.5 billion of the (very expensive) CRS program, the $6 billion of the "commercial crew vehicle" (and $3+ billion to build and launch the "commercial crew" hardware) can reduce the US manned spaceflight GAP from the Constellation's 8-10 years or the commercial space's 6-8 years to less than TWO years (starting now) or to ZERO (extending the Shuttle flights to 2012) and have lots of other advantages, like... have a TRUE independence from Russia, launching ALL the Soyuz it wants (and when it wants) without wait the availability of a "seat" on a russian launch, modify the Soyuz crew cabin and cockpit in english, to be piloted by american astronauts, launch up to THREE american astronauts per mission (instead of just one in the russian missions) accomplish the landing of the Soyuz in America (instead of Russia or the ocean like the Apollo, Orion, Dragon, etc.) and much more!
And, all these advantages should cost less than $2 billion (just 60% of the price of the CRS program or less than 35% of R&D costs of the "commercial crew vehicle" program) to buy 20 Soyuz rockets and capsules (for two crew missions per year in the next ten years) and 20 Progress for two-three cargo missions per year in the next seven-ten years, and it can save also on the launch pad costs adopting and modifying the (already built and paid but no longer used) Ares-1 launch pad, and the $15-20 billion saved can be used to develop an HLV.