Ulysses’s unexpected wobble

In 1990, shortly after launch, the Ulysses spacecraft started experiencing an unexpected wobble (nutation). This was because its 7.5-m boom unexpectedly flexed due to solar heating, affecting the spacecraft’s rotation and jeopardised the observations. Thanks to inventiveness of the Ulysses operations team, the problem was solved by an unconventional use of the spacecraft’s thrusters (used to manoeuvre and re-orient the spacecraft itself).