How many Rovers can we send to Mars for the cost of a manned mission? Would like to know, then equate the value extracted per dollar. I think it would be a no brainer, which is why we are considering "manned missions". Logical brains are not involved here. Those who are doing the design are not concerned with value only the political implications of such a mission. If you were vying for my vote a manned mission would be political suicide, but my opinion has not been asked. Spend the money on education, and bring back a valid education system.