Failure of reaction wheels often causes premature mission ending or failure to achieve the goal because spacecrafts are no longer able to maintain orientation and have to rely on chemical propellants. The Hubble telescope, Hayabusa spacecraft, Kepler telescope, Dawn spacecraft etc. all faced reaction wheel failure.
Recently there was a study that “space weather” induces electrostatic discharge between steel ball bearings and causes surface defects which eventually compromise the whole mechanism. But for me it’s hard to believe that this is the only reason, because I doubt that spacecraft only use steel ball bearings when ceramic, especially silicon nitride, are superior and can even survive lubricant starvation. What about contactless magnetic bearings?
Can “space weather” have other effects on flywheels like damaging permanent magnets (demagnetization), electronics, lubrication instead of steel ball bearings?