I understand that, which is why I said it never seemed strong enough to begin with. I get you need to conserve weight, but doing so on the wheels, seems, crazy? The most important thing of an entire car is the tires. Without good tires, a race car can't do anything, no matter how well engineered the rest of it is.

I think it's a gamble. If they made them thick enough to never break, they could have blown the whole weight budget. But if they make them too thin, the whole project is a waste.

I mean the wheels are probably among the heaviest single "things" on the rover, so adding even a small amount of thickness will really increase the weight, and that would mean cutting other things.

It's a tough call, and I'm sure as hell glad I wasn't the one that had to make it, but I think all things consitered they did a good job! It's been running for 5 years and even though these look bad, apparently it still has a lot of life left in it!

Surprisingly the wheels only weigh a few pounds each! (I still can't think in metric and I don't have a real number.)

They were primarily constrained by packing volume during cruise (https://mars.nasa.gov/msl/mission/spacecraft/cruiseconfig/) and then by shock loads as the securing pyrobolts blew during landing (https://youtu.be/Ki_Af_o9Q9s?t=4m14s).

I'm curious how you came to the conclusion that the wheels are the most important part of the rover.

Without wheels, the rover can not rove. Pretty much makes it useless if the wheels are broke, correct? Just like any vehicle, the wheel/tire is the most important piece regarding performance. Without good contact, all that fancy machinery won't do a thing.

Definitely, but couldn't you argue the same about other important components? For example, without an engine/motor, even the fanciest wheels will get you nowhere. I think it's somewhat of a paradoxical argument.

So the way I see it is that all of the major components are equally important, but you want to optimize your overall design to be both light and reliable.

Of course you could, that's why you don't skimp on those things. You can get by with a crappy interior, but things like wheels/tires/transmission/engine are high priority. That's my whole point here, it doesn't look like the wheels were over engineered enough, but I'm not a rocket scientist.

That wasn't clear from your original comment though. In case of the rover, other important things include comms/nav, movement controller, power source, and sensors.