Curiosity wheel damage: The problem and solutions
- What is the nature of the damage to the wheels?
- What is causing the damage to the wheels?
- What is the expected lifetime of the wheels, and how does that life end?
- How can they prolong the life of the wheels?
- Why didn't they foresee this problem?
- What are they changing for Mars 2020?
Introduction to Curiosity's wheels and suspension system
1. What is the nature of the damage to the wheels?
- The two rear wheels have scratches and dents but no holes that I can see anywhere (except for the odometry markings).
- On middle and front wheels, most (but not all) of the big holes are in the center section of the wheel -- that is, they are on the "crown."
- In some places, punctures and rips have coalesced to open very large holes.
- As far as I can tell, all of the skin that used to fill these holes is still attached and is projecting inside the tire.
- Rips tend to cluster at the tips of the chevron features.
- But there is virtually no damage to the skin inside the odometry markings, where grousers are closer together.
- There are no broken grousers and no sign of any damage (other than scrapes) to any of the stiffening rims.
- Even on the most-damaged wheels, you can clearly see from the outside where the stiffening ring is located, about a third of the way in from the outer edge. That stiffening ring is a locus of undamaged wheel: there is no obvious damage to the skin across this ring.
- There is no overall change in shape to any of the wheels.
2. What is causing the damage to the wheels?
3. What is the expected lifetime of the wheels, and how does that life end?
- Bedrock with lots of rocks: ~8 kilometers
- Lots of rocks, not on bedrock: 13-14 kilometers
- Bedrock with few rocks (think flagstones): 30-40 kilometers or more
- Smooth or sandy, with few or no rocks: indeterminate (causes no damage)