"MSL will operate on battery power."<br /><br />And where did you hear this? I recall an article from a while back saying one advantage to using RTG's would be not needing batteries, since the RTG provides power continuously.<br /><br />"it won't be driven at night"<br /><br />Wasen't this one of the reasons for using an RTG? So that the rover could operate continuously instead of just during high light levels? The only benefit of which I am aware MSL would get from operating during daytime would be the ability to use visible-light cameras without the need for forward facing lights (lol). <br /><br /><br />