Sending astronauts to Mars just to bring them home in a few weeks or months is a waste of money. Sending colonists to Mars to stay permanently would be a very good idea to prolong the human race, just in case
Maybe the human race (in its current form) was never intended to out last Earth.
I'm not saying I completely believe this, but I'm two chapters shy of finishing C.S. Lewis' Space Trilogy & felt compelled to post it.
Also, Sesh's post is spot on. And yes D@A, I am a nerd.