Forget about a manned mission to Mars. Let's challenge NASA to make a vehicle for earthlings.
Sigh, once again, someone calling to save us. "Save us mommy government." "We can't do it on our own!" "It's tooo hard".
NASA can't do squat. Certainly can't do anyhting cost effectively. Thinking that they could invent "an eliminate our dependence on foreign oil" car is a paradigm error. When you think of NASA, think Post Office. Yup, nothing good coming out of them but hire taxes.
How about this?
We close NASA. Nuke it. And with the 9B$ budget, we give a tax free 3B$ prize to the first verifiable entrepreneur who goes to the moon and returns. AND, we give a tax free 3B$ prize to the first carmaker who sells let's say 10 Million cars that get 100 mpg or better. AND, the last 3B$, we apply to the national debt.
Each year the prize goes unclaimed, we bump it up by the same amount.
My guess is that in three years, we will be up to our ass in cars and vacation offers to the moon.
You see the problem is that we don't try to see all public policy problems through economic glasses. It may be the best use of human talent, right this minute, that sneakers get made in some far away country rather than me trying to make my own. The fellow overseas will do a better job of it than I could and he will enjoy my writing. ;-)
Seriously, the economic cost of a 100 mpg car may not be the best use of scarce resources. The free marketplace gives us a very complex calculator that helps us decided if we really really want that ice cream cone or would we really rather have a beer. That complex calculator ensures that we have choices. It's only when the gumamint takes our money and makes choices for us (i.e., you want to go to the moon). They enslave us via money manipulation into believing that only government can solve a problem.
No, government is the problem!