Sorry to raise some cynical points but lets say...
1. Achieve something that genuinely grabs the public imagination again without a budget greater than the GDP of the United States.
2. Send manned missons ot space in a vehicle that is less likely to have them coming back to Earth as ashes.
NASA has seriously blotted its copybook recently - with an embarassing series of failures and Bush's proclamation about manned missions looking more like an attempt to be JFK than a genuine commitment.
Maybe a genuinely international approach as in the ISS might help with further manned missions - maybe it is stime for NASA to start taking a back seat to a present day UESPA?