Amusingly, in this case there were two chances. I'm saying if Spirit and Opportunity were constructed less well, perhaps we could have afforded a third with th

Amusingly, in this case there were two chances. I'm saying if Spirit and Opportunity were constructed less well, perhaps we could have afforded a third with the same budget. I don't really have any honest way to value the difference between 10 years of extra data vs another location (i'd guess the more data is better, but that's hindsight bias) Remember, every ounce of "factor of safety" is tens (or hundreds?) of thousands of dollars.