Mars Express has been using this solution for about a third of its 21 years in orbit.

In 2017, the flight control team noticed that four of the spacecraft’s six gyros were aging faster than expected, threatening to end the mission within two years. To save the mission, the solution was implemented and has been regularly updated ever since. Today the last upgrade would allow the spacecraft to function until 2034.

However, this solution was originally supposed to keep the satellite operational until mid-2025. Beyond this date, the gyroscopes would wear out due to their necessary use.

So how did mission control managed to extend the spacecraft in its third decade? By changing the definition of "necessary”.