During JPL’s IT Expo, Sawppy was on display and roaming around. Partway during the day, when setting up for a photo shoot, a shaft coupler tore out of Sawppy’s right-front steering servo. This was embarrassing and Sawppy limped along with some field repairs until the end of the day when we could analyze its failure and devise a path forward for all of Sawppy’s servos, not just the front-right wheel steering that failed.
On that day, the baseline JPL Open Source Rover was on display but was not driving because one of the steering couplers had failed on an earlier JPL outreach event and has yet to be repaired. Which wheel failed? The right-front wheel.
Even earlier – when the SGVHAK rover was just about to make its debut at SCaLE, a test drive session damaged the gearbox in one of the steering mechanisms. This required a short-term servo hack to get the rover back up and running in time for SCaLE. Which wheel was damaged and needed the hack? The right-front wheel.
Spirit, one of the actual rovers on Mars, has a recurring mechanical issue with one of its wheels. Which wheel was it? The right-front wheel.
Four rovers, same problematic wheel.
There are likely some perfectly logical explanations for why this might happen, but to the irrational human mind, such stories are where superstitions are born.