Sort of. I think the book "Roving Mars" covers this the best. They were worried about a dust storm like the one that killed Opportunity, so they designed the r

Sort of. I think the book "Roving Mars" covers this the best. They were worried about a dust storm like the one that killed Opportunity, so they designed the rover to last 90 days even in the pitch darkness of a dust storm. To make sure they'd succeed even in this worst case, they added two additional petals worth of solar panels (IIRC, about a 50% increase in area) to the MERs. Reading a contemporary description, they seemed to be very scared they wouldn't make the 90 days - hence this major and risky redesign. (The new panels had to open, and if one failed it would block off both the new solar panel, and one of the original ones.) It worked, and so they had enough extra power to last through that first Martian year, where the winds blew the panels clean. And the rest is history.