In response to:

>>>How many successfull projects have been completed with the prize approach?<<<

The most recent success story is Saddam's capture, although it's not clear that the informant will get the money.

>>>How many have been initiated?<<<

By NASA? Absolutely NONE. Despite Congressional support for prizes in NASA's budget, NASA's a jobs program, NOT a space program. But a real jobs program would implement competitive prizes like DARPA is doing. After all, "prizes often leverage as much as 40 times the amount of the prize in terms of overall private sector investment pursuing them."

>>>Has anyone who has accomplished a space mission supported this approach? <<<

The abovementioned quote is from Burt Rutan, and accompanies those of other X-Prize fans at:

http://www.SpaceProjects.com/prizes

Can you imagine what would happen if there was a space prize that's greater than a mere $10 million dollar amount? NASA could make it so, but...
It's worth noting an additional problem that exists in the absence of industry-enabling tax incentives: once companies secure their own funding, they desire to preserve their competitive advantages amidst limited market opportunities by NOT enabling others to get similar funding. Prizes would empower competitors, and so their support for prizes becomes less vocal once they've secured the funding that they need. Don't expect Elon Musk to support competitive prizes that vocally, for example. He's in the space business, not the altruism business. And if he wasn't, he'd not be in the space business for long. Our industry is that troubled.

>>>The problem with this whole idea that you can harness the benefits of capitalistic competition without much of a profit incentive. You expect people to do a lot of work to prepare a bid with no payback.<<<<

Actually, that sounds like the current contract bidding scenario.

>>> That's not how capitalism usually works. The risk of no payback is seldom tackled without a huge potential profit. Since minimizing profit is your goal your whole scenario is self contradictory.<<<<

How is minimizing profit my goal? Maximizing productivity, dollar-for-dollar, is.

>>> Since this is all economic theory rather than demonstrated fact,<<<<

Charles Lindberg would disagree.

>>> I'd support giving the method a shot on some lower priority target, but not the key goals of the space program.<<<<

Fortunately the FBI doesn't agree regarding pursuing its most wanted criminals.

>>>Regards, Mark<<<

Hopefully Astrium feels sufficiently tweaked into not lousing up the Beagle 2 mission while it can still hopefully be rescued. My prediction is NOT optimistic, though. Some failures are conveniently pre-ordained.