X Prize Foundation insured the $10 million prize it hadn't raised

Peter Diamandis modeled the X Prize on early 20th-century aviation prizes like the Orteig Prize that spurred Charles Lindbergh's transatlantic flight, betting a large enough cash prize could jump-start private, reusable manned spaceflight the way government space programs never had. But announcing a $10 million prize in 1996 required either having $10 million sitting in reserve, money the young foundation didn't have, or risking total credibility collapse and legal exposure if a team actually won and the foundation couldn't pay.

Raising the full $10 million upfront from donors, before any team had even attempted the challenge, meant asking philanthropists to fund a payout that might never be claimed for years, competing for the same money as causes with far more certain, immediate impact — a much harder ask than most nonprofit fundraising.

The foundation instead purchased what amounted to a hole-in-one insurance policy from underwriter XL Aerospace: for a fraction of $10 million in premiums, funded largely by the Ansari family, the insurer agreed to pay the full $10 million if any team actually succeeded, letting the foundation announce and stand behind a prize it hadn't fully funded.

Insured the payout instead of raising it: a small premium bought an underwriter's promise to pay the full $10 million if a team won, making the prize credible cheaply.

The insurance premium was a fraction of the $10M, so the foundation could afford it with limited funds.

The insurer priced the policy based on long odds, making the premium small.

The credible prize motivated teams because the payout was guaranteed by an insurer.

The foundation avoided the credibility collapse of an unfunded promise.

To make a large credible promise you can't fully fund, find a third party to underwrite the specific outcome; pay only the premium, not the full amount.

When SpaceShipOne won on October 4, 2004, underwriter XL Aerospace, not the foundation, paid the full $10 million purse. The insured-prize structure proved a cash-strapped organization could credibly back a huge incentive prize, directly inspiring Richard Branson's Virgin Galactic and a wave of subsequent X Prizes across other fields, funded the same way.