I'm fascinated by this -- the possibility that society will have to learn to live with some ineluctable limitations that, at present, many people probably imagine will be overcome because they think it's just a matter of time, effort etc.
So -- what if civilization endures but 200 years from now we are hardly closer to manned exploration of Mars than we are now? What if we have to accept that FTL is never going to happen? What if there is still, as now, absolutely no indication that other planets host life, let alone civilizations?*