I must add that landing two geologist-astronauts on a near-earth asteroid should be at the top of the White House space agenda, as recommended by David Kagan, US aerospace engineer and author of the book Sunstroke. I agree with Kagan: too many large space rocks are whizzing closer and closer to Earth, and top science panels state that it's now time to determine the best way to divert them--before it's too late. Kagan advises that NASA in conjunction with private industry mount a crewed- mission to the nearest one to accurately determine the precise composition of these dangerous bodies to prevent an extinction level event on Earth (or the loss of a major population center). Lockheed-Martin has already built and successfully launched their Ares heavy-lift rocket--the successor to the fabulous Saturn V booster that sent Apollo astronauts to the Moon--and has developed a viable flight plan to safely carry out a crewed- mission to a nearby large space rock.
Remember, that back in 1967 a panel of science experts urgently recommended that NASA put astronauts on a near-Earth asteroid for the same reasons using the giant Saturn V Moon rocket. Today, however, it will be far cheaper to "land" two astronauts on an asteroid using Lockheed-Martin's plan to "jet-pack" the crew to the asteroidal surface and back to their Command Module, without needing a landing vehicle akin to the Apollo lunar descent/ascent module. Such a mission would have a big pay-back return by safeguarding our civilization, therefore being infinitely more important than maintaining the ISS. The hands-on science results would be far more valuable and comprehensive than data return from unmanned probes.