The gambling website doesn't say how it came up with the figures, so I'll try to reverse engineer them. According to NASA, there are 112 qualified astronauts currently employed by the space agency. Let's bump that number up to 121 to include the 9 new ASCANs too. The U.S. population is 304,059,724 based on 2008 U.S. Census Bureau estimates. Dividing these two values, we arrive at a ratio of 2,512,890 to 1. That's a lot smaller than 12,100,000. Perhaps they just counted the size of one astronaut class. There were 11 astronauts chosen in 2004, for example. Dividing the U.S. population in 2004 (293,655,404) by this number yields 26,695,946. That's about twice as large as 12,100,000, so it's in the ballpark. I could probably make this estimate more exact by considering only the portion of the population actually eligible to be astronauts.
This type of analysis assumes a random probability distribution, implying that the chances for being chosen an astronaut (or President, saint, etc.) are equal for everyone. Of course, this isn't true in reality. Most people lack the right credentials to even apply for these jobs. Taking NASA's most recent selection, we see that 9 astronauts were chosen out of 3535 applicants. Of these applicants, only about 2800 were deemed "Qualified", so we could ascribe a selectivity of 9/2800 = 0.3%, which corresponds to odds of 311 to 1. That's more on par with your odds of marrying a millionaire or having your identity stolen. Of course, this estimate ignores the very real socio-economic barriers that prevent many people from even reaching a level to apply in the first place. Reality is probably somewhere between the 1 in 12,100,000 and 311 estimates.
If you want another chance for getting into space, you should check out the Starwalker reality show, which you can read all about over at Parabolic Arc. The competition will pit would-be astronauts against each other for the chance at two seats on a spaceflight. They will begin accepting entries on December 12 from anyone over the age of 18. An excerpt of the press release is below:
Starwalker is an inspirational reality TV show that demonstrates the accessibility of space, its benefit to humanity, the potential for private investment in space and the ability for the whole world to get involved in this New Age of Discovery, via a televised competition to select and train two astronauts from the ranks of the common global population, assisted by world experts in human spaceflight. The show culminates in two winners flying into orbit as fully-fledged astronauts on a Soyuz rocket. There will be two main competitions run in parallel: one for citizens of the Southern Hemisphere and another for those of the Northern Hemisphere, each involving physical, psychological and skills testing along with such activities as survival training, skills testing, joy flights and analogue studies. A significant portion of the show will be dedicated towards showcasing the facilities, achievements and projects of space agencies, companies and organisations around the globe to demonstrate the global nature and interconnectedness of the space industry and excite the public in a ‘Top Gear’ style approach.
Starwalker is the best, and indeed biggest, attempt ever made to create a permanent shift in the consciousness of the public back to the sense of wonder and the majestic human glory of the Apollo era. And Starwalker is a direct appeal to the people of the Earth, without the detrimental filtering effects of governmental or journalistic interpretation. Space experts will speak truth direct to the people, and the people will answer with the love and respect that space travel deserves.
A space-based reality series isn't a new idea, but if the press release is accurate Starwalker will be the first successful space reality show to finally get off the ground (literally, I hope!). They don't say specifically who is funding the project, only that funds are all "in place in trust and escrow." I find it interesting that they claim the show will be carbon positive "several times over, including the entire overseas carbon footprint of every aspect of the launch into space of each of the two winners." If this catches on, maybe every space launch can at least become carbon neutral. Famed theoretical astrophysicist Steven Hawking is supposedly even attached to the project too.
World Bank, the global population is 6,692,030,277, with about 90% of the people living in the northern hemisphere. Since the competition will chose one winner from each hemisphere, this means your odds are 1 in 6,022,827,249 in the north and 1 in 669,203,028 in the south. 6 billion vs. 700 million! Why the favoritism towards the southern hemisphere? The answer is simple: 2 of the 3 series co-founders are from Australia, and they want to boost their country's spaceflight stature. I can't be too angry at their decision; after all, they're fellow ISU alumni.
The Starwalker website isn't online yet (Nov 28 update: now it is), but you can stay in the loop by following its blog, Twitter profile, Facebook Group, or Facebook Profile.