What does basic economics say about that?
Nothing. Economics is a science, and economists are only concerned with things that are measurable and observable. What you're talking about is your own personal, subjective response to some major events. This has nothing to do with economics, and isn't even really a good proxy for what other people felt at the time.
For what it's worth, maybe you didn't care about 9/11 but I remember that I did, and so did everyone around me. Challenger wasn't a small thing, but it wasn't even close to 9/11. In the immediate aftermath, messages of condolences and support for the United States came from all around the globe, including from people like Fidel Castro, Vladamir Putin, and the North Koreans.
If we do go to Mars, I hope we don't do it for stupid, nationalistic dick-waving reasons. Space exploration has economic benefits, it's just that they're long-term ones. We should go and explore space because it's in our long-term interests to do so. We shouldn't forget about short-term things like infrastructure either, but they're not mutually exclusive.
And also, accomplishing exceptional things does not give a country free pass to mess with other countries and bully them.