If the human space flight program can't do much for $10 billion a year, then maybe it's time to look elsewhere for space development. We are just finishing the ISS at a total cost of something like $100 billion, so it would be silly to throw it away. Fortunately, the ISS 'only' costs about $2 billion/year, plus money to pay the Russians or American private companies to fly astronauts and equipment to and fro once the space shuttle is retired next year, say another $1 billion/year. Well utilized, the ISS could potentially produce useful biomedical research (there is at least one medication derived from ISS research that is starting trials), materials research, and technology test beds such as the recently cancelled space solar power demonstration project.
If the ISS costs $3 billion per year to operate, that leaves $7 billion/year for something else. The commission tells us this isn't enough to send a very small number of people to the Moon or Mars, so we should either reduce government expenditures or find something useful that $7 billion could do. I have proposed a $21 billion prize program to develop space solar power. This program is guaranteed to deliver at least 21 space power satellites or our money back. If successful, three years of money to not send a small number of people beyond Earth orbit may get space solar power up and running. This would have a revolutionary impact on energy and climate change problems as space solar power is very clean and available in gigantic quantities for the next few billion years.
Which do you think would benefit America, or for that matter, the world, more?
Finally, here's the kicker. A major reason NASA can't put people on the Moon or Mars with $10 billion a year is that transportation (launch) from Earth to orbit is expensive, several thousand dollars per pound. Launch is expensive because there aren't very many, fewer than 100 per year. Consider what a car would cost if the whole planet took only 100 car rides per year, total. If space solar power were successful, it would create a profitable market for many thousands of launches per year and the price would come down -- then NASA could put people on the Moon and Mars for much less than $10 billion per year.
So you don't even have to choose, you just have to be optimistic and believe that we can do pretty much anything the laws of physics allow if we really want to. America has the most capable aerospace industry in the world, some of the most dynamic entrepreneurs, and a desire for energy and a clean environment. With space solar power we have a shot, not a certainty, but a shot, at drastically reducing carbon emissions, becoming a major energy exporter, and a few years later putting people on the Moon and Mars. We just need to put $21 billion in escrow for a few years and pay it out if someone delivers on the dream. If they don't we get our money back.
Now that's a deal.