Re: Martian Winter
"They clearly designed it to last years. Probably could have survived 90 days without solar panels"
If you had built a device with an 80% chance of lasting 90 days, then as well as standing a 20% chance of dying during the initial period then statistically it's pretty certain it'd now be dead.
However, if you spec a device to have a 100% chance of surviving 90 days, that gives a very, very high statistical probability that it will still be running for many multiples of that time.
That it has lasted as long as it has though is more or less pure luck. If storms didn't periodicly blow the solar panels clear(er) then it'd be dead long ago from dust buildup on the solar panels. Since we didn't know about the storms before it's not something that could be planned for or expected.