As for Tom's point, again, *I* think that $49bn profit would be fine if someone pulled it off, but it would be easy to turn it into a political loser. For example, opponents would claim that the admin knew all along it would only cost $1bn but set such a high prize level due to the fact that the Vice-Prez' brother-in-law is on the board of the winning company.

You may be right, but if you want the hard truth, if someone came up with a new method that reduced the cost of a flight to Mars by two orders of magnitude, and by extension, the cost of flight into space (a necessary corollary), it would be worth Bush (or whoever) losing an election. Which is going to make the most difference to humanity in fifty years?