While the future of NASA's manned spaceflight program is in some doubt, there seems to be a building capability in the U. S. private sector to take on that challenge.
The best known of those attempts is no doubt Burt Rutan's elegant solution to suborbital flight. Teamed with British billionaire Sir Richard Branson's Virgin Galactic, Rutan's system will give paying customers a real taste of spaceflight starting next year, if all goes well. Interorbital Systems, however, plans to go VG one better. IOS plans to offer orbital flights starting in 2012. Then there is SpaceX's Falcon 9/Dragon configuration that plans to be capable of ferrying astronauts to and from ISS before NASA's Ares/Orion stack is ready-- so, well before 2015. There are also other efforts underway. If many such efforts succeed, competition among them can be expected to drive innovation, pushing ever more capable technology and producing ever more robust craft.
Internationally, China is moving ahead with manned missions, and India is considering a manned program of its own. ESA is weighing developing a manned capability independent of NASA, and Britain is mulling a manned capability independent of ESA. Japan clearly has the wherewithal to build a manned spaceflight program if it so chooses. There are also efforts outside the U. S. to create a private capability.
The Obama administration will no doubt look at NASA's immediate future within that broad context. So far, successors to the shuttle remain unproven, but if even a few of them prove their viability Washington will have to figure out how to remain a leading force in the exploration and development of space.