The person must actually go to space. It doesn't count if it's an edge case where they technically left the atmosphere but the experience was basically just being really high in the air, or something like that.
This market considers all three people to be trustworthy and will accept a low standard of proof (in addition to their word) that the space journey occured.
This market resolves to "No one goes to space" if there is no activity on Manifold from each of @Tumbles, @Mira_, and @strutheo for six consecutive months. Alt accounts count as activity if moderators are reasonably certain the accounts do in fact belong to the same person.
@Nat Yes! Everybody remains eligible until the market resolves, so it only takes one of the users being active to keep the market open