Humans will probably never bother with Mars, it's just not a good fit for us. We barely live in Antarctica right now, and that's on Earth, where we can get all of the oxygen and water that we need for living there. Sending humans to space seems to have become irrelevant, as robots are much more efficient and easier to send to space than humans these days. Back in the 60's, when the Moon race was on, computer technology had not yet advanced to points they are at now, so there was no choice but to send human astronauts, as they are more flexible in carrying out missions. But these days robots are very flexible too, just look at the Curiosity Mars Rover, it has a built-in laser beam to burn through Martian rocks and analyze their composition with spectrometers built into the rover itself! Not only is it doing geology by itself, it's also doing chemistry up there too!
Now there is a worry that humans are running out of space here on Earth, as our populations keep growing. But evidence is already suggesting that human population growth has plateaued.
Space travel for humans will happen if we have a destination to go to in space. So for the most part, nobody really has anywhere to get to in space right now. I think the first destination in space that humans will have a serious reason to get to will eventually be the Moon. As far as mining asteroids in space, I think that will be done mostly by robots, no need for humans.