I think there are going to be some very serious mental health issues for people trying to colonize Mars, especially if they're taking a one way trip. First, you have to deal with a different day-night cycle and the reduced gravity. That stuff matters for humans who have gotten used to 24 hour days and 9.807 m/s^2 gravity over the last 200,000 years.<p>Then, you're going to have to deal with boredom and cabin fever. Mars seems cool in the abstract--"explore another world!"--but its just a big, completely dead desert. I'm betting the novelty of it will wear of in an hour (tops) of landing there. There really isn't that much for humans to learn by going there in person. Those people will just have to stay in a tiny space for years on end without a lot to do. Think of what a bust the video game No Man's Sky was. People hated it because it was boring. But I'm sure exploring planets in that game was much more interested than Mars will be.<p>As the years go on, loneliness and despair will set in. Those first colonists will likely spend the rest of their lives pretty much with who they landed with. Their lives won't change much at all over the decades they're there, and they'll have no hope for things to ever be different.<p>Settling to Mars seems so glamorous, but it really will not be a fun affair. It'll be extremely expensive, really depressing, and probably pointless.