How did the mars rovers survive on mars?
It’s not so much that they wre not expected to survive, it’s that they were designed to last *at least* 90 sols. They have survived past expectations, and one of the main factors believed to be responsible is that the winds on Mars are cleaning the solar panels of dust. This was believed to be the limiting factor in the lifespan of the rovers. The solar panels were expected to get covered in dust to an extent that would prevent them functioning, but occasional stroms have cleaned them and allowed them to keep functioning beyond original expectations. The rest of it is down to brilliant engineering.
