5 years of thrusting? can you please stop now?

[IamNemo85]

All this talk of what a robot can produce scientifically, versus having boots on the ground, it doesn't really matter, the fact we are boldly going forth and experimenting with new things is what truly matters. We as a species must place more money and faith in our science programs. We talk about spending money on renewable resources and replacing our dependence on fossil fuels instead of on Space Exploration, but I propose that truthfully funding man spaced exploration, or robotic for that matter, is an investment in renewable resources and new forms of energy. These are all technologies that would be vital in the future of space exploration. Historically, these industries have grown parallel with our space programs, it's only after we as a people, lost touch with what the space programs do for us, that we cut funding and those industries had to struggle for funding. I say, bolster the Space Program (be it manned or robotic) and you bolster all of mankind!

[Burke112]

NTRs are promising and the research could definitely be started up again. The problem with them is mainly that the public distrusts anything with the word "nuclear" in it so the politicians aren't so keen to fund it.

NASA has a politics problem more than a money problem. We could have human missions to Mars in 20 years for ~$100 billion. That's only about a 25% increase to NASA's current budget, or about 0.03% of the US's GDP.

On topic, higher power ion engines are very promising. High-power versions like the one that would be developed for the asteroid retrieval mission could be used to send cargo for human missions to Mars.

Apparently, NTRs are being tested once again -- http://www.nasa.gov/topics/technology/features/ntrees.html#.UdjGtvm1Fu4

Apparently, the Nuclear Cryogenic Propulsion Stage is supposed to be used for the whole "manned mission to Mars by the 2030s" thing.