> real mission: colonizing Mars. If you have critical information stored on a hard drive, it’s common sense to back up the info on a second hard drive.<p>It's common sense to back up critical information on a second hard drive. Now say you had only one hard drive and no realistic way of getting a second one. Would it be common sense to work on sending people to a beach on the other side of the world, asking each of them to write as many words as they can remember in the sand, with a stick? At this point you would be working on organizing the logistics of sending all those people there, and saying "we think we will find a way to solve the problem of people forgetting/misremembering words and the information changing later, but now it's revolutionary that one person made the trip and wrote the first words". Without ever considering that on a beach, there is wind and sometimes water that will erase your text.<p>Would you call that common sense?<p>> We’re fortunate to have another potentially livable rocky planet nearby. Why not try to use it?<p>Because it is <i>not</i> potentially livable. We should quit our denial and accept that our species does not need that. Our species needs to stop killing its habitat, period.<p>Don't get me wrong: it's cool to make big rockets. It's technically impressive. It's probably a very interesting military project for the US (looking forward to having all kind of nations sending missiles in orbit /s).<p>But what it is not, at all, is "one of the major milestones in not just human history but life history—on par with the moment animals first began to walk on land".