Yes and no. They're usually quite good, but they wear out. Reaction wheels are in continuous use and must remain precise enough to negate spin within some very

Yes and no. They're usually quite good, but they wear out. Reaction wheels are in continuous use and must remain precise enough to negate spin within some very tight tolerances. With limited fuel and the inherent work and risk in doing a burn to cancel spin, reaction wheels are usually spun very fast before they burn off the spin and let the wheels slow back down.