45 days of rover = 30 seconds of manned == unbelievable horsesh*t. It made a nice quote but is ridiculous on the face of it. Any manned exploration will have to be aided by robots and tools to do most of the real work. The fact that rovers are slow now, doesn't mean we can't design a next generation much faster and effective (already in the offing). Meanwhile how would humans get around on mars (how much weight of vehicles and supplies must you bring to support their wanderings?).

Spectrometer readings still have to be taken. How much manned geological exploraton now really relies on instrumental analysis of samples?

ROBOTS ACTUALLY RETURN MONEY. That is why you don't count up all the development costs. There are many economically viable uses for robots and robot technologies. Their development and advancement is mostly paid for by those uses. Applying available robot technology for space doesn't mean you have to start from scratch.

Now, on the contrary, what economic return has manned space technology given us that we wouldn't have arrived at by other means? What viable use is it here on earth? Once again most of the technology development has to do with getting humans to survive up there, not for any direct efficiency improvements or science return.

Like I've said over and over and over again, humans will have their day in space ONCE LAUNCH COSTS ARE CONSIDERABLY CHEAPER. When that day comes, robots will be incredibly more sophisticated and will probably do most of the heavy lifting to support the human presence off world.