Really colonization/terraforming would be nice, but if that never happens -- think of all the technologies like CAT Scans that will be developed while we 'try' to terraform Mars. As global warming gets worst we might even discover a cure for issues with our own planet by looking for solutions into making Mars more livable.

Scientific discovery whether it fails or succeeds will never hurt us or set us back, it's failure to keep momentum going that will. Space tech hasn't really evolved like other industries in the past 40 years because interest has dried up. It's now starting to see a revival, and I for one am excited, and would like to take a space trip on the ITS around the solar system which may be a possibility.

If I can't go to mars, I'd still love a chance to go see the rings of Saturn from a space hotel. That would be worth every dollar, and crashed rocket.