Hard to do that from orbit though, getting those solid bits up there takes some work. And when you're on the ground if you're relying on auto-navigation your av

Hard to do that from orbit though, getting those solid bits up there takes some work. And when you're on the ground if you're relying on auto-navigation your average speed is less than 1km/day so hard to get a wide survey. Take the current curiosity mission as an exemplar. It is coming up on having been on the ground for 7 years (August '12). A human team, with the same instruments, and a rover could have achieved all of the science results from Curiosity to date, in less than a month. Further they could have repaired instruments that have become non-functional from spares carried with them. Opportunity and Spirit covered a combined 36 miles or so in 10+ years of operations, also doable in about a month by a human crew. So we have nearly two decades of robotic exploration that we could do in about 3 months with a group of people and some transport. Plus they could do additional research that the robots can't because they could combine the instruments in ways the robots cannot, or use different processes the robotics cannot implement. I realize this sounds like a dismissal of the huge accomplishment and contribution to science that the rovers have made. It is not my intent. Those are valuable things, and some science is always better than no science. What I'm trying to point out that putting people there would have 100x the science return for less than 100x the budgetary impact.