There's two big issues with this approach: 1) death is but only the worst outcome. Being on the space shuttle does bring risk, yes, but not a 50/50 chance of a

There's two big issues with this approach: 1) death is but only the worst outcome. Being on the space shuttle does bring risk, yes, but not a 50/50 chance of a significant impact to your general health. 2) you'll end up testing the vaccines largely on marginalized population and people with heavy financial problems, misrepresenting the population at large and showing biased result.