Six astronauts “blasted off” Thursday on the Mars 500 on a 520-day simulated journey to determine how the crew members cope with the problems and tedium of a long-duration spaceflight. The all-male international groupâmdash;three are Russian, one French, one Chinese, and one Italian born in Colombiaâmdash;will spend the next year and a half in a chain of metal capsules in a hangar at Moscow’s Institute for Biomedical Problems, where they will perform daily flight tasks and experiments, participate in a simulated spacewalk on Mars, and deal with “emergency” situations. A real mission to Mars is decades away, however.