Tom wrote: "The beauty of the "prize" idea is that if nobody comes up with anything that works, it costs the government exactly nothing. What do they have to lose? Financially, at least."

This is certainly true, which is why I will never argue that there should be no X prize. But there is a line of thinking that 'anti-Space' factions in our Gov't like to trot out that goes something like:

"NASA is an evil empire *preventing* cheap access to space (usually no justification given). We should do away with NASA and offer a package of incentives to industry instead".

(Notice, I am not saying this is your argument, you will get no Straw Man stuff out of me )

I find this argument to be entirely political. It is another way of killing the space budget. It never really quantifies what 'package of incentives' means. It also does not offer any real data about how, even with assistance, industry could conduct the development of Manned and profitable RLVs or SSTOs.

Personally, I am for an X prize. In fact, my daydream would be to work on a project that would take the X-prize Unfortunately, I just lack faith that any project is going to take the X prize in the next decade, or that 100mil is any sort of realistic incentive.